Help diagnose where the slop is..

J

JTProuhet

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I have a lot of driveline slop compared to a couple other CRs that i have drove.. I have been told that it could be the splines where the driveshaft goes into the transfer case.. There is a little play, not much, in the slip joint part of the driveshaft, and i have no clue how to check the rear end for the proper mesh, It is really driving me crazy. Has anyone else had this slop in their truck? It only has 71k miles on it and it was a grandpas truck before i bought it at 51k and ive never done any boosted launches or hooked up to anything, besides trailers.. Any help would be greatly appreciated.
 
Pull the shaft and check the yolk as well as the u joints. U joints are probably due for replacement anyway. Get the Spicers and be done with it. Also check the carrier bearing.

While the shaft is out, set the parking brake (Should be already unless you're using a lift.) and grab the pinion yolk. I'm not sure of the lash spec, but work it back and forth and see if it seems excessive. I'll try and find the spec, if someone knows it feel free to add.
 
Amish Elegance said:
Pull the shaft and check the yolk as well as the u joints. U joints are probably due for replacement anyway. Get the Spicers and be done with it. Also check the carrier bearing.

While the shaft is out, set the parking brake (Should be already unless you're using a lift.) and grab the pinion yolk. I'm not sure of the lash spec, but work it back and forth and see if it seems excessive. I'll try and find the spec, if someone knows it feel free to add.
Click to expand...

Alright i will do that! Thanks. I have gotten under there before and checked the u-joints, and they seem tight, i dont feel or see any play in them moving them back and forth, I know one of them have been replaced from OEM because all of them have grease fittings, and i know for sure one of them was replaced right before i bought it cause it was going out when i looked at it and i told him he had to replace it before i bought it...

And i have set the parking brake and left it out of gear, and there is play in the pinion yoke, and I think that there is too much, like I can rotate it maybe, 1/4"-3/8".. So i got under my friends 08 that only has 15k on it and it has about the play, so i didnt think that was it, but it is really annoying..
 
Oh, If someone could post up the specs for the pinion lash, please post! Thanks guys
 
Actually i just remembered that i had a service manual for my truck downloaded on my work computer.. I guess this is what i was looking for correct?

AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.73, 4.10
Ring Gear Diameter 292 mm (11.5 in.)
Ring Gear Backlash 0.13-0.18 mm (0.005-0.007 in.)
Pinion Bearing Preload - New Bearings 1.69-2.82 N·m (15-25 in. lbs.)
Pinion Bearing Preload - Original Bearings 1-2 N·m (10-20 in. lbs.)
Pinion Bearing Preload + Differential Case Bearing
Preload - New Bearing
3.4-5.6 N·m (30-50 in. lbs.)
Pinion Bearing Preload + Differential Case Bearing
Preload - Original Bearing
2.8-5.1 N·m (25-45 in. lbs.)
 
Nah. I'm not sure there is a pinion lash spec. The ring gear backlash requires a dial indicator on the ring gear.

I'm not sure if there's a spec for lash that can be measured outside the case on the pinion shaft itself. Anyone?

If you pull the shaft, check the slip yolk out too.
 
alright.. so this is a dumb question, but im going to ask anyways.. which one is the slip yoke? isnt that the one that goes into the transfer case? And how much is too much play in the carrier bearing?
 
I took some pictures of my carrier bearing to see if you guys think it needs replaced and if u guys think this might be where my slop is.. Here is a shot of the top half of it..
379edabe.jpg


and the bottom
8ad9236c.jpg


I assume that it should be pretty well centered in the carrier and mine has a gap in the top half.. The next thing I'm gonna do is like you said pull the shaft and check all the u-joint real good
 
does it clunk when changing directions? once tight does it go away? A buddie of mine had the back lash way off truck only had 26,000 miles.
 
smokingoat04 said:
does it clunk when changing directions? once tight does it go away? A buddie of mine had the back lash way off truck only had 26,000 miles.
Click to expand...

It is hard to explain.. it only does it like cruising down the road at a constant speed and let out of the pedal, and then hit the pedal again.. like there is slack when i let off the pedal and then when i hit the pedal, the slack goes away and clunks.. I almost think that, that could be my same problem too, but i have no clue at all.. and it doesnt look like the carrier bearing is helping either.. I got under it the other night, i had my parking brake set, left it neutral, and grabbed the yoke on the pinion at the rear axle and it would spin maybe 1/4-1/2" back and forth.. but i dont know what is supposed to be.. And i dont know anyone that knows anything about rear ends (like setting them up as far as lash)...
 
and it will do it when im shifting gears if i dont keep the rpms up to where the should be at the speed im going compared to the gear im going in (make sense? hard to explain)
 
Amish Elegance said:
Nah. I'm not sure there is a pinion lash spec. The ring gear backlash requires a dial indicator on the ring gear.

I'm not sure if there's a spec for lash that can be measured outside the case on the pinion shaft itself. Anyone?

If you pull the shaft, check the slip yolk out too.
Click to expand...

Best I remember on the DANA 70s and 80s you shim the two pinion bearings and torque them up, then check the rotational force needed to make it turn with an in-lb torque wrench. The only other adjustement for it is to offset it forward or rearward for gear mesh. It's done with the carrier out.

Not sure with the AAM's.

Jack the rear end up, Put the truck in gear, if its an open diff, have someone hold one side. Rotate the other and watch what rotates when you turn the one tire. If you have a noticable clunk it should be visible like this.

Naturally if it's a limited slip you should only have to turn the one side.

Either you or a helper will need to lay underneith and watch for what consumes the slack.
 
Alright so I pull the back cover.. Backlash is within specs.. There is a little play in the differential it seems like.. And a little play in the slip joint.. Nothing too terrible.. I just think that it all adds up to be a bit of play.. So I guess next think on the list is a 1 piece driveshaft.. Has anyone had or hears of anyone haveing any problems with play in the tranny or t case? All the u-joints are tight carrier bearing could probably be replaced but all the rubber is still intact just a little cracked..
 
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