1972 Ck-10 4x4

[Keith Wilks]

I have replaced approx. (3) complete rear-ends in my 72 4x4 over the 15 years I have driven it. It always sems to start with the pinion bearing seal going out and water / dirt entiering the differential housing. Could this p. seal be getting damaged by the excessive amount of slack in the drive train? It's an automatic transmission and going out of park to reverse / drive really makes a clang a lot of the time. I thought after this last rear differential rebuild that some of the slack would be taken out, but it is still there.

Where would I start looking to take the slack (spin up) out of the transmission, transfer case, and rear end. When I say slack or spin up I am talking about the amount of rotation in the drive shaft before it stops after engaging the transmission.
Thx,
K.

[krue]

I can't help you, but welcome to the board from South Mississippi. You came to the best place to get an answer.

[LUV2XCLR8]

2 the board from west 10-uh-c

[Longhorn Man]

Welcome to the best board on the web.

Have you looked at the pinion angles? Do you have a crazy lift on it?

[Yukon Jack]

I'm sorry I don't know anything about auto trannys so I can't help but welcome and I hope someone will have some suggestions for you. You might want to also post this in the 4x4 Discussion forum.

[Keith Wilks]

Originally Posted by krue

I can't help you, but welcome to the board from South Mississippi. You came to the best place to get an answer.

Thanks, I am seeing the benifits already.
K.

[Keith Wilks]

Originally Posted by Yukon Jack

I'm sorry I don't know anything about auto trannys so I can't help but welcome and I hope someone will have some suggestions for you. You might want to also post this in the 4x4 Discussion forum.

Thanks, for the welcome. You fellers have a good thing going here.
K.

[Keith Wilks]

Originally Posted by Longhorn Man

Welcome to the best board on the web.

Have you looked at the pinion angles? Do you have a crazy lift on it?

Thanks, No I have not thought about "Pinion Angles" I suppose you mean the angle that the drive shaft intersects the pinion gear?

No "Crazy Lift" only a 2" lift kit or actually just 2" worth of metal shims.
K.

P.S....What a great place to get information.

[Longhorn Man]

2 inch is cool, however, with just metal shims, and not proper blocks, there is a good chance that your pinion angle is wrong.

angle that the drive shaft intersects the pinion gear

Close enough... you got the idea.

I would recomend getting rid of the shims, and either going with out, or getting proper lifting blocks. They are pretty cheap if I am not mistaken. I don't know much about checking the pinion angle, nor what the specs are for stock, or a modified set up.... but I'm sure some one here will chime in with more info.

[3qtrtontarrer]

it sounds like your pinion depth and backlash need to be adjusted, there ere specs for these. i had the same issue with my dana 60. replaced 3 diffs after blowing them up 1 at 75mph on the interstate. it felt like the tranny dropped out of it , werst noise ive ever heard. what rear are you using.

[jhow66]

Have you checked your rear housing vent tube?

[Stocker]

Welcome from NorCal! I have 2" rear lift blocks (Skyjacker). Height at the rear is ~2 1/8", and 1 15/16" at the front, for a difference of ~3/16" over the length of 4 3/4". Not sure what the angle works out to, maybe someone can figure it out.

[Keith Wilks]

Originally Posted by 3qtrtontarrer

it sounds like your pinion depth and backlash need to be adjusted, there ere specs for these. i had the same issue with my dana 60. replaced 3 diffs after blowing them up 1 at 75mph on the interstate. it felt like the tranny dropped out of it , werst noise ive ever heard. what rear are you using.

I just had the rear end rebuilt completely everything is new and I suppose in proper adjustment as well? I made a step up from the standard differential and installed a 308 Eaton p-track. If this $1750. job explodes like yours did.......it will be the worst sound I've ever heard!!
K.

[Keith Wilks]

Originally Posted by Stocker

Welcome from NorCal! I have 2" rear lift blocks (Skyjacker). Height at the rear is ~2 1/8", and 1 15/16" at the front, for a difference of ~3/16" over the length of 4 3/4". Not sure what the angle works out to, maybe someone can figure it out.

Thx,
k.

[Keith Wilks]

Originally Posted by jhow66

Have you checked your rear housing vent tube?

I did replace this a few years back and plan to do so again, soon. I even plan on finding a hose end filter / valve as well. Not sure where to look for such a thing, but don't want water / dirt to get in the diff. housing.

Do you have any advise?

Thx,
K.

[Keith Wilks]

Originally Posted by Longhorn Man

2 inch is cool, however, with just metal shims, and not proper blocks, there is a good chance that your pinion angle is wrong.

Close enough... you got the idea.

I would recomend getting rid of the shims, and either going with out, or getting proper lifting blocks. They are pretty cheap if I am not mistaken. I don't know much about checking the pinion angle, nor what the specs are for stock, or a modified set up.... but I'm sure some one here will chime in with more info.

Thx,
K.

[jhow66]

Originally Posted by Keith Wilks

I did replace this a few years back and plan to do so again, soon. I even plan on finding a hose end filter / valve as well. Not sure where to look for such a thing, but don't want water / dirt to get in the diff. housing.

Do you have any advise?

Thx,
K.

I doubt that you are getting water and dirt through your pinion seal because it would have to be almost gone to do this. (gear oil would be running out). Does the vent have a hose on it that goes up under the bed? Do you drive it withe the rear end under water?

[Keith Wilks]

Originally Posted by jhow66

I doubt that you are getting water and dirt through your pinion seal because it would have to be almost gone to do this. (gear oil would be running out). Does the vent have a hose on it that goes up under the bed? Do you drive it withe the rear end under water?

Just prior to replacing the entire rear end a couple of weeks ago there was a little fresh oil seeping out all the way around the pion seal area and blowing back on the housing. I don't go through much water anymore just the occasional standing water on the street etc.
Yes, I do have a fairly new vent hose that is snaked up into the I-beam area and the end is lower than the highest part of the hose.
Thx,
K.

[jhow66]

Have you replaced the pinion yolk. The pinion seal will wear a groove in the yolk. New seal will only last a very short time as it runs in the same groove.

[1969 C/K CST]

Experiencing any axle wrap? Rough driving and offroading combined with axle wrap can play he!! on alignment and equipment. Depends on how you use it and what you want to do. I personally don't care for shims or blocks. For 2" you could use a new rear spring. Just my opinion.

[Keith Wilks]

Originally Posted by jhow66

Have you replaced the pinion yolk. The pinion seal will wear a groove in the yolk. New seal will only last a very short time as it runs in the same groove.

I looked at my invoice that I had the mechanic itemize for future reference and in the parts list there is a "Ring and Pinion set", but no pinion yoke. Surely this would have been replaced with the extensive amount of work I had done, but I will check to see if it has been or not.

Thanks, your answer, that along with pinion angle is figuring into the reoccuring seal damage problem.
K.

[Keith Wilks]

Originally Posted by 1969 C/K CST

Experiencing any axle wrap? Rough driving and offroading combined with axle wrap can play he!! on alignment and equipment. Depends on how you use it and what you want to do. I personally don't care for shims or blocks. For 2" you could use a new rear spring. Just my opinion.

My first thought when I took my truck in to be worked on was that the rear end was bent, so while the rear end was being replaced the mechanic checked my it for true and it was OK. Both axles / bearing were also replaced in the overhaul.

I had the springs all re-sprung, but did not know about the extra spring idea at the time, but that makes good sense and I will look into this more.
Thx,
K.