Pop quiz - what do you think the problem is?

[alia176]

Ok boys and girls, it's time to put on your thinking cap and solve this puzzle! A solution for this particular issue has been found but I think it's good exercise for y'all. Remember to pay close attention to Cause and Effect as you read the scenario.

Vehicle:
150k miles
Front DS splines cleaned out and regreased prior to this.
All original suspension bushings.

Symptoms:

1) when coming to a stop sharply, the Transmission shifter moves back and forth. The tip moves about 1/2".
2) you can recreate this isse by simply pressing and depressing the brake pedal while slowly moving forward. A distinct "clunk" is heard and is felt through the steering column.
3) while the "clunk" is being heard, you can look at the radius arm bushings and they're being compressed quite heavily. I'm referring to the bushings that sit directly behind the front axle on the control arm. The front bushings don't seem to have as much compression.
4) while off roading, you can watch the Transmission shifter move fore/aft as the suspension cycles over rough terrain.

Troubleshooting:

1) when driving with just the rear DS in the vehicle (CDL locked) you can really make the Transmission lever move back and forth. This is apparent while accelling hard or coming to a brisk stop.
2) when driving with just the front DS in the vehicle (CDL locked), all of these symptoms go away.
3) motor mounts are new
4) Tcase mounts don't "seem" sloppy but don't know for sure.
5) Drove home from Moab with both grease fittings removed from DS, no improvement.

Question:

What do you think is the problem?

Ali

 

[CruisinGA]

motor/transmission mounts

 

[Hants]

Transmission/TCase mounts cracked?

 

[concretejungle]

Ali, how can you look at the arm bushings while coming to a stop?

 

[NorCalDoug]

transfer case mounts

 

[landtank]

What do you think is the problem?

A Heep DIYer worked on the poor thing and now it's screwed for life.

 

[Stumpalama]

Overgreased driveshaft... do one do both.

 

[Slomo]

Transmission/t-case mounts

 

[cruiserdan]

Ali, how can you look at the arm bushings while coming to a stop?

You do it in my driveway while I watch then I drive and he watches.

 

[cruiserdan]

motor/transmission mounts

Motor mounts new, did not change it.

 

[cruiserdan]

I'm thinking maybe rear driveshaft slip yoke.

 

[Cruiser Jimmy]

A ghost pain from owning a Rover.

In what direction is the knob moving when the fat pedal is pressed and when the skinny pedal is pressed?

 

[alia176]

The answer is....



Slip yoke on the rear driveshaft. Even though the slip yoke moved freely in/out, there was about an 1/2" of old grease trapped way in the end. This was enough to cause the hydro-locking. Driving with the grease fittings removed weren't enough to release that last amount of grease. After removing the rear DS from the vehicle, I used all of the my body weight to squeeze the two halves and quite a bit of stuff came out of the grease fitting hole. Then everything was cleaned out and in went the Schaefer #2xx (can't recall at the moment) syn grease and now all is well. So, now you know the cause.

The effects were:
-tranny moving fore/aft
-tranny shifter moving with the suspension cycling
-the "clonk" was from the rear output bearing getting slammed twice - loading and then a quick unloading of the rear pinion.

Pat yourselves on the back!

Ali

 

[cruiserdan]

So then,


I guess that means I win?............











And don't even go there about the part that we did not isolate that in my driveway.....














Remenber I know where you are going to live.......

 

[alia176]

Remenber I know where you are going to live.......

Damn it..... I shoulda kept my mouth shut!!!

 

[MaddBaggins]

I had a similar issue when I had my front DS removed. I bet I have some old grease caked in the rear DS. I guess I better check that out. Thanks Ali.

 

[Cruiser Jimmy]

Nice going there Ali, I cleaned out both shafts today and reduced the clunk a little. I still have some slope in the Tcase which continues to give me a clunk when shifting from R to D.

Thanks for the help.

 

[Tentsontop]

Nice.

 

[Slomo]

Good information, thanks for sharing.