'97 Suburban trans problem
Question:
>Robbie, >In the absence of a hands-on diagnosis by a decent AT mechanic, you have >to assume that the tranny needs replacing. If you’re going to be towing, >get a HD rebuild like www.jetchip.com or www.tciauto.com. The 4L60E (I’m >assuming K1500 here) is notorious for dying from towing in OD which is a >real possibility here. You’ll need to install the largest tranny cooler >that you can fit on the truck.
Aren’t tranny coolers standard equipment on Suburbans???
Response:
– Hide quoted text — Show quoted text ->Hi: >I feel compelled to offer my ?cents worth here. I recently bought a >used ’96 GMC Yukon with about 78K miles on it. Had driven the truck >almost 500 miles over a several week period before purchase. No >indication of problems. Then about three weeks ago I came off the >interstate into a parking lot and heard a rumbling, grinding noise. One >tranny guy said it was the planetary that controlled 1st and Rev. His >comment was when you can’t stand the noise anymore you’ll come and have >it rebuilt, but it will never leave you stuck on the road. Then about a >week ago I suddenly experienced a lack of power, inability to pull, >(almost like a fuel obtruction) and no reverse. When cold it functioned >normally but when it got warm it failed catastophically. >Local GMC dealer evaluated and suggested a GM SRTA Transmission rather >than a rebuild. More expensive but warranted for 50,000K miles or three >years. They also suggested a new radiator as according to them the >tranmission oil cooler frequently gets clogged and even with an >auxiliary oil cooler would cause the new tranny to fail from >overheating. I was sceptical, but told them to go ahead. After the >radiator was removed you could look in the inlet side of the >transmission cooler and see that the passages were totally blocked. The >stuff was packed in there so tight that no amount of solvent flushing >ever would have gotten it out.
<snip> Anyone here have thoughts on placing a cool thermostat in during the summer hot months? I had a 90 suburban that seemed to run much better with the cool thermostat. Now I have a 97 that I am thinking about doing the same to but have also heard that there are temp sensitive sensors that might act up if I were to do this. thoughts?
Response:
Really? They print them for a reason? My 1999 GMC Yukon owners manual says: "You should tow in OVERDRIVE. You may want to shift the transmission to THIRD or, if necessary, a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions). That is an exact quote, including the caps. At any rate, I was just asking for opinions. I know what the manual says.
– Hide quoted text — Show quoted text -> They print owner’s manuals for a reason. It will tell you NOT to tow in > OD under ANY circumstances. The ONLY GM AT that can tow in OD is the 4L80E. > Dean >Is that 4L60E what was used on a ‘99 Yukon? I just bought one of these to >pull a 4,000 lb. travel trailer. It has the tow package and 3.73 rear end. >The rated tow capacity is 7,000 lb., so I’m not close to that. I was >assuming that I could tow in OD, and I think there is an auxiliary trans >cooler in front of the radiator. I was previously using an 88 Safari to >tow. It never had any transmission problems despite not having added an >auxiliary cooler until about a year prior to replacing it with the Yukon. I >usually used 3rd towing with it. Do you have any opinion regarding whether I >need to tow in 3rd or put a larger tranny cooler on the Yukon? >Thanks for any replies, ’spud
– Hide quoted text — Show quoted text ->>Robbie, >>In the absence of a hands-on diagnosis by a decent AT mechanic, you have >>to assume that the tranny needs replacing. If you’re going to be towing, >>get a HD rebuild like www.jetchip.com or www.tciauto.com. The 4L60E (I’m >>assuming K1500 here) is notorious for dying from towing in OD which is a >>real possibility here. You’ll need to install the largest tranny cooler >>that you can fit on the truck. >>The MIL lamp may have nothing to do with the tranny at all. You’ll need >>somebody with an OBDII scan tool pull the code(s). >>To each his own but let me suggest you take a pass and think about a ‘95 >>or earlier K2500 with the 8600# GVWR package (454/4L80E). It will pull a >>5,000# trailer so easy you’ll have to look in the mirror to make sure >>it’s still there! Trust me, I have one! And the biggest benefit is that >>the 4L80E tranny can tow in OD so your towing mileage may be better with >>the 454/4L80E than a 350/4L60E. >>Dean >>>I am currently looking into buying a ‘97 Suburban with 145000 miles on >>>it. The only mechanical problem with the truck is the transmission >>>will not go into overdrive. It has a 5.7 and is 4X4. The trans >>>shifts fine into 2nd and 3rd. There are no noises, no grinding nor >>>slipping noted at all. The check engine light comes on and stays on >>>while the engine is running. I have seen some good answers to many >>>questions about transmissions answered here, so I have come here first >>>for some advice. I know this is not a lot of info on the truck, but I >>>have only looked at it for about 1 hour yesterday. I would greatly >>>appreciate if someone could give me some ideas about what could be >>>wrong. I will be using the truck mostly for driving to town (about 25 >>>miles one way) and for towing a 5000# travel trailer about four times >>>a year (starting on flat ground of the coast and ending up 300 miles >>>later in the mountains of North Carolina). The body and interior of >>>the truck are in excellent condition. The engine started fast when >>>cold and hot. I did not see any smoke when cranked or on hard >>>acceleration. The engine idled perfect cold and hot. There were no >>>delays noted when the trans was put into drive or reverse. I know it >>>is hard to diagnose a prblem without seeing the vehicle, but any and >>>all suggestions would be greatly appreciated. >>>Thanks, >>>Robbie.
Response:
>>>The MIL lamp may have nothing to do with the tranny at all. You’ll need >>somebody with an OBDII scan tool pull the code(s). >right on again. The code may have nothing to do with the trans other >than some codes cause the ECM to not let the trans shift into OD. >Then again, you could have the dreaded P1870 code which usually >requires replacement of the valve body. >If this code does come up, then could the valve body be replaced >without rebuilding the entire transmission if the rest of the trans is >in good shape?
Yup, they do ‘em all the time.
Response:
They print owner’s manuals for a reason. It will tell you NOT to tow in OD under ANY circumstances. The ONLY GM AT that can tow in OD is the 4L80E. Dean – Hide quoted text — Show quoted text – >Is that 4L60E what was used on a ‘99 Yukon? I just bought one of these to >pull a 4,000 lb. travel trailer. It has the tow package and 3.73 rear end. >The rated tow capacity is 7,000 lb., so I’m not close to that. I was >assuming that I could tow in OD, and I think there is an auxiliary trans >cooler in front of the radiator. I was previously using an 88 Safari to >tow. It never had any transmission problems despite not having added an >auxiliary cooler until about a year prior to replacing it with the Yukon. I >usually used 3rd towing with it. Do you have any opinion regarding whether I >need to tow in 3rd or put a larger tranny cooler on the Yukon? >Thanks for any replies, ’spud >Robbie, >In the absence of a hands-on diagnosis by a decent AT mechanic, you have >to assume that the tranny needs replacing. If you’re going to be towing, >get a HD rebuild like www.jetchip.com or www.tciauto.com. The 4L60E (I’m >assuming K1500 here) is notorious for dying from towing in OD which is a >real possibility here. You’ll need to install the largest tranny cooler >that you can fit on the truck. >The MIL lamp may have nothing to do with the tranny at all. You’ll need >somebody with an OBDII scan tool pull the code(s). >To each his own but let me suggest you take a pass and think about a ‘95 >or earlier K2500 with the 8600# GVWR package (454/4L80E). It will pull a >5,000# trailer so easy you’ll have to look in the mirror to make sure >it’s still there! Trust me, I have one! And the biggest benefit is that >the 4L80E tranny can tow in OD so your towing mileage may be better with >the 454/4L80E than a 350/4L60E. >Dean >>I am currently looking into buying a ‘97 Suburban with 145000 miles on >>it. The only mechanical problem with the truck is the transmission >>will not go into overdrive. It has a 5.7 and is 4X4. The trans >>shifts fine into 2nd and 3rd. There are no noises, no grinding nor >>slipping noted at all. The check engine light comes on and stays on >>while the engine is running. I have seen some good answers to many >>questions about transmissions answered here, so I have come here first >>for some advice. I know this is not a lot of info on the truck, but I >>have only looked at it for about 1 hour yesterday. I would greatly >>appreciate if someone could give me some ideas about what could be >>wrong. I will be using the truck mostly for driving to town (about 25 >>miles one way) and for towing a 5000# travel trailer about four times >>a year (starting on flat ground of the coast and ending up 300 miles >>later in the mountains of North Carolina). The body and interior of >>the truck are in excellent condition. The engine started fast when >>cold and hot. I did not see any smoke when cranked or on hard >>acceleration. The engine idled perfect cold and hot. There were no >>delays noted when the trans was put into drive or reverse. I know it >>is hard to diagnose a prblem without seeing the vehicle, but any and >>all suggestions would be greatly appreciated. >>Thanks, >>Robbie.
Response:
> The 4L60E (I’m >assuming K1500 here) is notorious for dying from towing in OD which is a >real possibility here. You’ll need to install the largest tranny cooler >that you can fit on the truck.
Amen >The MIL lamp may have nothing to do with the tranny at all. You’ll need >somebody with an OBDII scan tool pull the code(s).
right on again. The code may have nothing to do with the trans other than some codes cause the ECM to not let the trans shift into OD. Then again, you could have the dreaded P1870 code which usually requires replacement of the valve body.
Response:
– Hide quoted text — Show quoted text -> The 4L60E (I’m >assuming K1500 here) is notorious for dying from towing in OD which is a >real possibility here. You’ll need to install the largest tranny cooler >that you can fit on the truck. >Amen >The MIL lamp may have nothing to do with the tranny at all. You’ll need >somebody with an OBDII scan tool pull the code(s). >right on again. The code may have nothing to do with the trans other >than some codes cause the ECM to not let the trans shift into OD. >Then again, you could have the dreaded P1870 code which usually >requires replacement of the valve body.
If this code does come up, then could the valve body be replaced without rebuilding the entire transmission if the rest of the trans is in good shape? Robbie.
Response:
Is that 4L60E what was used on a ‘99 Yukon? I just bought one of these to pull a 4,000 lb. travel trailer. It has the tow package and 3.73 rear end. The rated tow capacity is 7,000 lb., so I’m not close to that. I was assuming that I could tow in OD, and I think there is an auxiliary trans cooler in front of the radiator. I was previously using an 88 Safari to tow. It never had any transmission problems despite not having added an auxiliary cooler until about a year prior to replacing it with the Yukon. I usually used 3rd towing with it. Do you have any opinion regarding whether I need to tow in 3rd or put a larger tranny cooler on the Yukon? Thanks for any replies, ’spud – Hide quoted text — Show quoted text – > Robbie, > In the absence of a hands-on diagnosis by a decent AT mechanic, you have > to assume that the tranny needs replacing. If you’re going to be towing, > get a HD rebuild like www.jetchip.com or www.tciauto.com. The 4L60E (I’m > assuming K1500 here) is notorious for dying from towing in OD which is a > real possibility here. You’ll need to install the largest tranny cooler > that you can fit on the truck. > The MIL lamp may have nothing to do with the tranny at all. You’ll need > somebody with an OBDII scan tool pull the code(s). > To each his own but let me suggest you take a pass and think about a ‘95 > or earlier K2500 with the 8600# GVWR package (454/4L80E). It will pull a > 5,000# trailer so easy you’ll have to look in the mirror to make sure > it’s still there! Trust me, I have one! And the biggest benefit is that > the 4L80E tranny can tow in OD so your towing mileage may be better with > the 454/4L80E than a 350/4L60E. > Dean >I am currently looking into buying a ‘97 Suburban with 145000 miles on >it. The only mechanical problem with the truck is the transmission >will not go into overdrive. It has a 5.7 and is 4X4. The trans >shifts fine into 2nd and 3rd. There are no noises, no grinding nor >slipping noted at all. The check engine light comes on and stays on >while the engine is running. I have seen some good answers to many >questions about transmissions answered here, so I have come here first >for some advice. I know this is not a lot of info on the truck, but I >have only looked at it for about 1 hour yesterday. I would greatly >appreciate if someone could give me some ideas about what could be >wrong. I will be using the truck mostly for driving to town (about 25 >miles one way) and for towing a 5000# travel trailer about four times >a year (starting on flat ground of the coast and ending up 300 miles >later in the mountains of North Carolina). The body and interior of >the truck are in excellent condition. The engine started fast when >cold and hot. I did not see any smoke when cranked or on hard >acceleration. The engine idled perfect cold and hot. There were no >delays noted when the trans was put into drive or reverse. I know it >is hard to diagnose a prblem without seeing the vehicle, but any and >all suggestions would be greatly appreciated. >Thanks, >Robbie.
Response:
Hi: I feel compelled to offer my ?cents worth here. I recently bought a used ’96 GMC Yukon with about 78K miles on it. Had driven the truck almost 500 miles over a several week period before purchase. No indication of problems. Then about three weeks ago I came off the interstate into a parking lot and heard a rumbling, grinding noise. One tranny guy said it was the planetary that controlled 1st and Rev. His comment was when you can’t stand the noise anymore you’ll come and have it rebuilt, but it will never leave you stuck on the road. Then about a week ago I suddenly experienced a lack of power, inability to pull, (almost like a fuel obtruction) and no reverse. When cold it functioned normally but when it got warm it failed catastophically. Local GMC dealer evaluated and suggested a GM SRTA Transmission rather than a rebuild. More expensive but warranted for 50,000K miles or three years. They also suggested a new radiator as according to them the tranmission oil cooler frequently gets clogged and even with an auxiliary oil cooler would cause the new tranny to fail from overheating. I was sceptical, but told them to go ahead. After the radiator was removed you could look in the inlet side of the transmission cooler and see that the passages were totally blocked. The stuff was packed in there so tight that no amount of solvent flushing ever would have gotten it out. If I had just gone to a local transmission shop for a rebuild that’s what they would have done without ever getting to the root cause of the failure which was restricted flow through the transmission fluid cooler on the side of the radiator. I guess what I’m saying is that it is quite obvious that all of the systems(cooling) associated with the transmission need to be very carefully examined and proven functional or an expensive rebuild would be for naught. For what it’s worth, Bob
Response:
> I am currently looking into buying a ‘97 Suburban with 145000 miles on > it. The only mechanical problem with the truck is the transmission > will not go into overdrive. It has a 5.7 and is 4X4. The trans > shifts fine into 2nd and 3rd. There are no noises, no grinding nor > slipping noted at all. The check engine light comes on and stays on
With that many miles, you can bet the transmission is bad or is going bad. I you do buy it, allow for the cost of re-building the transmission. There are upgrades that make the 4L60E more durable for towing. Make sure to get these while you’re at it. This will take care of the "tow in OD" problem and make this marginal transmission into a pretty good one for a half ton truck. Since you have 4×4 you must have either 3.42:1 or 3.73:1 gears. Mine has the 3.42 setup. I towed about 5500 lbs last weekend for about 250 miles. This was on hilly twisty roads. No mountainous, just constant up and down stuff. At speeds between 55 and 60, the tachometer stayed closer to 2000, than to 2500 the whole time. (I kept it in third gear). It never had to downshift into 2nd. I think it would have held overdrive at higher speeds on flat ground.
Response:
Dean, Thanks for your advice on the trans problem. It is a K1500. I understand what you are saying about getting a K2500 instead, but my thinking was I only put maybe 2,000 miles a year (out of 15-18,000) pulling my trailer. I currently own a ‘89 K1500 LWB reg. cab truck, 5.7 and auto trans that I pull the trailer with. It does ok in the mountains and gas mileage is terrible, but I think the mileage is great when running empty (16-17 mpg). Also I only drive maybe 400 miles in the mountains a year, so strain on the truck is minimal. I always pull with trans in drive and normally only go about 60 mph. When I am pulling the trailer I am not in any hurry, so I don’t push my truck hard except on one 3 mile climb. If I could have the trans rebuilt and expect to get 75-100k out of it, I would be happy ( I say this because I realize pulling my trailer a few times a year does put a lot of strain on it) . The owner of the truck only wants $9500 for it. I do have a good automatic trans mechanic I trust. He has done transmissions for me and others I know with no complaints from anyone that I have ever heard. If I was going to be putting more miles pulling the trailer I would consider the K2500, but since the vast majority of my miles is running light, I feel the savings on gas will make up for any repair costs in the future. My main concern now is spending more buying the truck and repairing than the truck is worth. Once again thanks for the advice. Robbie – Hide quoted text — Show quoted text ->Robbie, >In the absence of a hands-on diagnosis by a decent AT mechanic, you have >to assume that the tranny needs replacing. If you’re going to be towing, >get a HD rebuild like www.jetchip.com or www.tciauto.com. The 4L60E (I’m >assuming K1500 here) is notorious for dying from towing in OD which is a >real possibility here. You’ll need to install the largest tranny cooler >that you can fit on the truck. >The MIL lamp may have nothing to do with the tranny at all. You’ll need >somebody with an OBDII scan tool pull the code(s). >To each his own but let me suggest you take a pass and think about a ‘95 >or earlier K2500 with the 8600# GVWR package (454/4L80E). It will pull a >5,000# trailer so easy you’ll have to look in the mirror to make sure >it’s still there! Trust me, I have one! And the biggest benefit is that >the 4L80E tranny can tow in OD so your towing mileage may be better with >the 454/4L80E than a 350/4L60E. >Dean >I am currently looking into buying a ‘97 Suburban with 145000 miles on >it. The only mechanical problem with the truck is the transmission >will not go into overdrive. It has a 5.7 and is 4X4. The trans >shifts fine into 2nd and 3rd. There are no noises, no grinding nor >slipping noted at all. The check engine light comes on and stays on >while the engine is running. I have seen some good answers to many >questions about transmissions answered here, so I have come here first >for some advice. I know this is not a lot of info on the truck, but I >have only looked at it for about 1 hour yesterday. I would greatly >appreciate if someone could give me some ideas about what could be >wrong. I will be using the truck mostly for driving to town (about 25 >miles one way) and for towing a 5000# travel trailer about four times >a year (starting on flat ground of the coast and ending up 300 miles >later in the mountains of North Carolina). The body and interior of >the truck are in excellent condition. The engine started fast when >cold and hot. I did not see any smoke when cranked or on hard >acceleration. The engine idled perfect cold and hot. There were no >delays noted when the trans was put into drive or reverse. I know it >is hard to diagnose a prblem without seeing the vehicle, but any and >all suggestions would be greatly appreciated. >Thanks, >Robbie.
Response:
I am currently looking into buying a ‘97 Suburban with 145000 miles on it. The only mechanical problem with the truck is the transmission will not go into overdrive. It has a 5.7 and is 4X4. The trans shifts fine into 2nd and 3rd. There are no noises, no grinding nor slipping noted at all. The check engine light comes on and stays on while the engine is running. I have seen some good answers to many questions about transmissions answered here, so I have come here first for some advice. I know this is not a lot of info on the truck, but I have only looked at it for about 1 hour yesterday. I would greatly appreciate if someone could give me some ideas about what could be wrong. I will be using the truck mostly for driving to town (about 25 miles one way) and for towing a 5000# travel trailer about four times a year (starting on flat ground of the coast and ending up 300 miles later in the mountains of North Carolina). The body and interior of the truck are in excellent condition. The engine started fast when cold and hot. I did not see any smoke when cranked or on hard acceleration. The engine idled perfect cold and hot. There were no delays noted when the trans was put into drive or reverse. I know it is hard to diagnose a prblem without seeing the vehicle, but any and all suggestions would be greatly appreciated. Thanks, Robbie.
Response:
Robbie, In the absence of a hands-on diagnosis by a decent AT mechanic, you have to assume that the tranny needs replacing. If you’re going to be towing, get a HD rebuild like www.jetchip.com or www.tciauto.com. The 4L60E (I’m assuming K1500 here) is notorious for dying from towing in OD which is a real possibility here. You’ll need to install the largest tranny cooler that you can fit on the truck. The MIL lamp may have nothing to do with the tranny at all. You’ll need somebody with an OBDII scan tool pull the code(s). To each his own but let me suggest you take a pass and think about a ‘95 or earlier K2500 with the 8600# GVWR package (454/4L80E). It will pull a 5,000# trailer so easy you’ll have to look in the mirror to make sure it’s still there! Trust me, I have one! And the biggest benefit is that the 4L80E tranny can tow in OD so your towing mileage may be better with the 454/4L80E than a 350/4L60E. Dean – Hide quoted text — Show quoted text – >I am currently looking into buying a ‘97 Suburban with 145000 miles on >it. The only mechanical problem with the truck is the transmission >will not go into overdrive. It has a 5.7 and is 4X4. The trans >shifts fine into 2nd and 3rd. There are no noises, no grinding nor >slipping noted at all. The check engine light comes on and stays on >while the engine is running. I have seen some good answers to many >questions about transmissions answered here, so I have come here first >for some advice. I know this is not a lot of info on the truck, but I >have only looked at it for about 1 hour yesterday. I would greatly >appreciate if someone could give me some ideas about what could be >wrong. I will be using the truck mostly for driving to town (about 25 >miles one way) and for towing a 5000# travel trailer about four times >a year (starting on flat ground of the coast and ending up 300 miles >later in the mountains of North Carolina). The body and interior of >the truck are in excellent condition. The engine started fast when >cold and hot. I did not see any smoke when cranked or on hard >acceleration. The engine idled perfect cold and hot. There were no >delays noted when the trans was put into drive or reverse. I know it >is hard to diagnose a prblem without seeing the vehicle, but any and >all suggestions would be greatly appreciated. >Thanks, >Robbie.
