viscous coupler

j10jeep

New member
Hi guys I am new hear and I have a grand wagoneer.My problem is when I drive it and stop, sometimes it will grind and buck and wont move.I put it in nutral and back in gear and it will drive normal. The transmission shifts normal.I am thinking it is the viscous coupler.PLEASE HELP. Mark
 

Hi guys I am new hear and I have a 1987 grand wagoneer with a 360 and a 727 trans.My problem is when I drive it and stop, sometimes it will grind and buck and wont move.I put it in nutral and back in gear and it will drive normal. The transmission shifts normal.I am thinking it is the viscous coupler.PLEASE HELP. Mark
 
Is your rear end making any noise. When it "won't move" is it binding or slipping?
Grinding, bucking and locking up or kind of jamming instead of slipping (viscous coupler) may indicate a ring gear (or pinion) problem.

Might want to check out the IFSJ site, lot of old timers on there.
 
I thought it was the rear end.I took the cover off and the rear is ok. It is a slipping noise.It sounds like the driveshaft is spinning and the jeep is trying to move.When it is moving everthing is fine up to 60mph then you hear a groning sound. Mark
Is your rear end making any noise. When it "won't move" is it binding or slipping?
Grinding, bucking and locking up or kind of jamming instead of slipping (viscous coupler) may indicate a ring gear (or pinion) problem.

Might want to check out the IFSJ site, lot of old timers on there.
 

Drive Shaft Check....... does it have a "carrier" bearing at a crossmember or bracket somewhere. If not check your universal joints and yokes.
Jimmy
 
I looked it up and you likely have a NP 229 transfer, which I've never had to deal with.
Just as a test, I'd take off the front drive shaft and put the transfer in lock and see what happens.
I'm guessing it is a full time, part time setup.

Just on a guess, does your passing gear work? The passing gear cable (or linkage) also controls pump pressure. If the cable or linkage is disconnected, the mechanism will set itself to the lowest possible pressure.

Remember you have to check transmission fluid level with the motor running. I know it's simple, but I tend to start with simple first, then move on to complex, then expensive.
 
I looked it up and you likely have a NP 229 transfer, which I've never had to deal with.
Just as a test, I'd take off the front drive shaft and put the transfer in lock and see what happens.
I'm guessing it is a full time, part time setup.

Just on a guess, does your passing gear work? The passing gear cable (or linkage) also controls pump pressure. If the cable or linkage is disconnected, the mechanism will set itself to the lowest possible pressure.

Remember you have to check transmission fluid level with the motor running. I know it's simple, but I tend to start with simple first, then move on to complex, then expensive.
I did all the checks and everything seems to be ok.I only got it to do this a couple of times,The trans shifts fine and downshifts ok.The passing gear also works fine.It sounds like I lave a bad ring and pinion but it is in good shape to. Mark
 
In 4x4 or 2wd? If in 2wd, the VC isn't in use. Sometimes the rear diff bearings can go bad and it will feel like the trans.
 

check trans pump pressure. just because the fluid is full does not mean that the trans is ok. what does the fluid look and smell like. if it is dark and has a smell dirrefent than that of new fluid i would be suspect of the trans.
 
check trans pump pressure. just because the fluid is full does not mean that the trans is ok. what does the fluid look and smell like. if it is dark and has a smell different than that of new fluid i would be suspect of the trans.
Ok I think some of you dodn,t read the post correct or I didn,t ask the correct question.I will try it again.The problem I am having is the jeep has a grinding noise sometimes when go to take off.It sounds like the rear diff ring gear teeth are broken.I ckecked the rear and it,s ok.This noise is a gear to gear noise or a spline to spline noise.
 
If you are gassing it when you start to drive and it makes that chunk, chunk chunk sound it may be the chain slipping in your transfer.
Possible your parking pawl is adjusted wrong and making contact in some situations.
I'd grab the rear pinion and try to move it sideways and look and see if it isn't leaking oil. If your pinion bearings are loose, under some conditions it will make that noise.
Pinion bearings or carrier bearings usually cause a loud growl when they go bad, that gets worse when accelerate and changes pitch when you coast.
 

Hello mark,

I am starting to have the same problem on my 90GW, were you able to have an answer from someone and find what was the problem ? if you have please let me know @ ccohen1 (at) hotmail.com

Thnx

CC
 
Pull the front driveshaft off and if the vehicle drives fine its probably your viscus. Rember to park flat and use your e brake because the vehicle will roll slowly in park. Found that out first hand when wife parked our GC at grocery store and it rolled into a Harley. Woops.
 
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