88 suburban 4 Wheel drive selector popping out of 4wd when var bumps slightly

[Rockhounder]

Annoying to say the least, the 4wd gear shifter goes back into 4Hi, I drive along, then the tiniest vibration or bump bounces the handle back into 2Hi. Have had to end up putting an empty Sobe bottle in front, against the heater vents. to keep it from bouncing out of gear. I know there should be a detent, to prevent this, but any of you out there ever had to experience this, and how did you fix it so it would stay in 4Hi?

Thanks
paul

 

[Larry]

Annoying to say the least, the 4wd gear shifter goes back into 4Hi, I drive along, then the tiniest vibration or bump bounces the handle back into 2Hi. Have had to end up putting an empty Sobe bottle in front, against the heater vents. to keep it from bouncing out of gear. I know there should be a detent, to prevent this, but any of you out there ever had to experience this, and how did you fix it so it would stay in 4Hi?

Thanks
paul

Yeah, that is pretty common on high mileage 208 and 241 transfercases in both GM and Dodge rides. There are nylon pads on the shift forks that wear with age and after a while they fall out of 4hi back in to 2wd. The nylon pads are still serviced by GM dealers (sorry, I don’t have the pn) and they are a pita to replace as the entire case has to be taken apart. The good thing is they’ll last you another 25+ years.

Another thing to look at are the engine mounts and rear trans mount. My Polar Bear was falling out of 4 hi back in to 2wd as well but I found the rear trans mount was broke allowing the engine and trans assembly to move sideways yanking the lever back down. That is much easier to check and fix over the shift pads. Good luck!

 

[Rockhounder]

Yeah, that is pretty common on high mileage 208 and 241 transfercases in both GM and Dodge rides. There are nylon pads on the shift forks that wear with age and after a while they fall out of 4hi back in to 2wd. The nylon pads are still serviced by GM dealers (sorry, I don't have the pn) and they are a pita to replace as the entire case has to be taken apart. The good thing is they'll last you another 25+ years.

Another thing to look at are the engine mounts and rear trans mount. My Polar Bear was falling out of 4 hi back in to 2wd as well but I found the rear trans mount was broke allowing the engine and trans assembly to move sideways yanking the lever back down. That is much easier to check and fix over the shift pads. Good luck!

Thanks,

Will check that, (mounts). Then on to replacing the pads, might as well do that anyway, as 88 to now is 26 years anyway!

 

[superbuickguy]

if you want to keep it on the road, NP 208s are pretty unloved in the 4x4 community, so they're as common as rain the PNW - meaning, you should be able to find out at your pick n pull for $50 or so (or find one on CL), rebuild that one so you don't have to take yours down too long.

 

[warwgn]

the detent bolt is on the bottom of the tcase in line with where the selector rod come out of the case and about 4 inches back. if it is worn out the selestor will be free to jump around easy as you saying. Dont know the part number but it would be easy to change, but when you pull it out trans fluid will come out too.

 

[warwgn]

whoops wrong pic....