Problems with 4 low
Question:
Sounds like a problem in the t-case itself… GMC’s are great trucks and the dealer network seems to be pretty good, though I haven’t really used it. I’m looking toward a new truck in the next year or so (got mine used), though I have a GMC I am considering a Dakota Quad cab since I won’t be able to afford the GM I want (the Avalanche). The midsize trucks in the Dodge lineup (Dakota, Durango) are nice trucks, my brother and father have a Dakota and Durango respectively, both are extremely happy, though my brother has had problems with a supposed "Five Star service center". Enough about Dodge, for full size GM is the only way to go IMHO. – Hide quoted text — Show quoted text – > Mike – I don’t have shift on the fly. To engage 4 low, I have to > stop, put the truck in neutral, and jam the sucker into 4 low. > Then when I put it in back in drive, the truck starts shaking. I > push the gas pedal down and the engine revs but the wheels don’t > turn. I opened my window in the pouring rain and the wheels > won’t even spin on wet grass. They are not getting any power. > This happens about 90% of the time. The other 10% or the time, 4 > low actually works and I can drive somewhere. > I am not actually trying to fix the problem. I am not a mechanic > and I can’t even imagine what this would cost. I am really just > trying to find out if this is a common GM problem or a fluke. I > am thinking ahead to what truck I want next and I am sick of all > the problems I have had with my GMC truck, although when it runs > well I love it. I don’t want to jump ship and go with a Ford and > I don’t like the Dodges. I really want a Toyota Tundra but can’t > afford one. Go ahead, crucify me. > Got questions? Get answers over the phone at Keen.com. > Up to 100 minutes free! > http://www.keen.com
Response:
Thanks, Mike. 4WD high works fine. I have had this problem with 4 low on wet grass and in the snow. I don’t have manual locking hubs. Are you suggesting that I should remove the 4WD fuse and put the truck in 4 low? Sorry to be stupid, but what would that accomplish? Got questions? Get answers over the phone at Keen.com. Up to 100 minutes free! http://www.keen.com
Response:
Are you stopping before trying 4LOW? You have to, even with "Shift on the fly" 4WD. And then keep in mind you won’t be able to go as fast as in 4WD HI or 2WD. – Hide quoted text — Show quoted text – > Thanks, Mike. 4WD high works fine. I have had this problem with > 4 low on wet grass and in the snow. > I don’t have manual locking hubs. Are you suggesting that I > should remove the 4WD fuse and put the truck in 4 low? Sorry to > be stupid, but what would that accomplish? > Got questions? Get answers over the phone at Keen.com. > Up to 100 minutes free! > http://www.keen.com
Response:
If you remove the 4wd fuse, then the front hubs will not lock. You can shift into 4wd Lo Range, only you will be in 2wd Lo Range. If the truck still doesn’t move easily (and slowly) then you have a problem with lo range in your transfer case. The fact that 4wd hi range works well also implies the lo range in the transfer case is a problem. I use 2wd Lo Range (fuse pulled) when I am on dry pavement, but I want the slow speed and controlled movement of low range. My truck idles at less than 1mph in lo gear, lo range. Perfect for backing into tight spots or manuvering under my camper, etc. You may be able to live without low range at all. It is usefull for very steep hills (up or down), moving very heavy loads, creeping over off road obstacles, but not much else. All on road activities and 90%+ off road activities can be done with only hi range. No 2wd trucks even offer the lo range of a transfer case. Total use of lo range on both my trucks is about 10 miles total in 35,000 miles of use. Mike L 99 Silverado 1500 Base 4×4 4.8L 5spd 00 Silverado 2500 LS 4×4 6.0L 5spd (Delivery 5-12) Deadhorse, Alaska 6-6-99 Before you buy.
Response:
Mike – I don’t have shift on the fly. To engage 4 low, I have to stop, put the truck in neutral, and jam the sucker into 4 low. Then when I put it in back in drive, the truck starts shaking. I push the gas pedal down and the engine revs but the wheels don’t turn. I opened my window in the pouring rain and the wheels won’t even spin on wet grass. They are not getting any power. This happens about 90% of the time. The other 10% or the time, 4 low actually works and I can drive somewhere. I am not actually trying to fix the problem. I am not a mechanic and I can’t even imagine what this would cost. I am really just trying to find out if this is a common GM problem or a fluke. I am thinking ahead to what truck I want next and I am sick of all the problems I have had with my GMC truck, although when it runs well I love it. I don’t want to jump ship and go with a Ford and I don’t like the Dodges. I really want a Toyota Tundra but can’t afford one. Go ahead, crucify me. Got questions? Get answers over the phone at Keen.com. Up to 100 minutes free! http://www.keen.com
Response:
>Mike – I don’t have shift on the fly. To engage 4 low, I have to >stop, put the truck in neutral, and jam the sucker into 4 low. >Then when I put it in back in drive, the truck starts shaking. I >push the gas pedal down and the engine revs but the wheels don’t >turn. I opened my window in the pouring rain and the wheels >won’t even spin on wet grass. They are not getting any power. >This happens about 90% of the time. The other 10% or the time, 4 >low actually works and I can drive somewhere.
Sounds like a linkage adjustment to me. Sometimes you are probably hitting the lever harder and actually getting it to go in gear, some times you aren’t. 4low has no synkros, so if you happen to get stopped in the neutral position while shifting, and you continue to try to shift, the turning parts in the t/case will grind. When this happens, shut off the engine, and try shifting into 4 low then. See if it won’t work like that. Big Daddy ICQ#6342575 ASE Master Auto Technician Chevrolet Certified Master Tech.
Response:
I have a ‘96 GMC 2500 pickup truck. When I shift into 4 low it doesn’t put any power to the wheels. The whole truck shakes like it’s about to stall out. I don’t have any lift kits or any after-market stuff on my truck. Is this common with the GM trucks? I plan on trading in this truck for a new one in a year or 2. If this is a common problem I might even go with the Ford (oh horrors!) Got questions? Get answers over the phone at Keen.com. Up to 100 minutes free! http://www.keen.com
Response:
Are you doing this on pavement or off the road? Does 4wd hi range work ok? Lo range is just like hi range, only with more gear reduction. On pavement, even small differences in tires size (one 35 psi, rest 30psi) can cause the system to bind up. The slight difference in size means they have to travel different distances, and the mechanical parts of the truck make them run the same speed. Even turning a corner can cause this. In the dirt, tires just slip. On pavement, something has to give, and it is harder to make a tire slip. If 4wd Hi works fine, and 4wd Lo does not, then you have a problem. Try 4wd Lo with the front wheels unlocked (Manual hubs – unlocked or Auto hubs – remove the 4wd fuse) to see what happens. Good Luck, Mike L 99 Silverado 1500 Base 4×4 4.8L 5spd 00 Silverado 2500 LS 4×4 6.0L 5spd Deadhorse, Alaska 6-6-99 Before you buy.
