Front pinion angle cj5

[blaylock6502]

My 74 at some point in time developed another leak. I looked underneath and found the front pinion seal leaking. While I was looking I noticed the pinion is actually pointing down.? Does anyone know what the pinion angle should be? Also are the saddles welded to the axle tube where they would require being cut off? I'm not really sure if maybe it is a different axle than what came in it ? Or it has had a shackle reversal kit installed would that require changing the front pinion angle? Thanks!

 

[PoliceMonkey161]

You should have a Dana 30 axle. It would look like the one below. The saddles or perches (if we are talking about the same thing?) could be cut off, but it's a real pain as they are casted (I believed?). I don't know excatly what the angle would be (depends on the amount lift and type of lift)? But I do know it should be in an upward cant. If it matters, a leaking pinion seal is common and easy to fix. But the under-laying problems of the angle still needs to be addressed.


I know someone here is going to ping me on this, but you can change the pinion angle using shims, which will also improve your steering geometry as well. If done correctly steel shims using pins or steaks, is far easier,faster and requires no special equipment to install. Cutting off the factory perches will involve a lot of grinding and smoothing. Then you'll have to re-install the perches (which are aftermarket and not as solid) at the correct angle. But that would be if you actually have the Dana 30 front?


That's my two cents worth......

 

[blaylock6502]

I love the Lucas advertisement u should sell that police monkey!!!!! Lol. Ill take a pic tonight and send it to you if u don't mind looking at it! It has no suspension lift. Thanks!

 

[PoliceMonkey161]

Yes.....Please send photos. I was thinking about this problem the whole time while BS'ing with the Chief after shift and the drive home. I've never seen a pinion that inverted? Do you have a reverse shackle lift........

The photo is from a write up I did in the "how-to" section about rebuilding a Dana front axle. Love Lucas stuff! Use it my Cummins, Mustang and Jeep........ Good stuff!

 

[blaylock6502]

Here are some pics I don't know if u can see the pinion but its def pointed down!!!

 

[blaylock6502]

Def not as pretty as yours policemonkey but it still breaks my heart to even get it on gravel

 

[Bounty__Hunter]

Your pinion angle is correct if the ujoint at the transfer case has the same operating angle as the pinion ujoint. To put it differently, the pinion and the transfer case front output shaft should be parallel as in the pic below:

Is it possible a previous owner modified the axle to increase caster, thus pointing the pinion downward? This is often done in an attempt to improve the steering wander inherent in old CJ's.

 

[blaylock6502]

It handles awesome but does shake in reverse but I assumed for a long time it was the clutch shuddering as the valve cover leaks more oil than it holds! I would have to look at the working angle of the t case. For that to be correct the front of the t case would have to be pointed down, correct?

 

[Bounty__Hunter]

I would have to look at the working angle of the t case. For that to be correct the front of the t case would have to be pointed down, correct?

No. For the ujoint angles to be correct the t-case output would need to be pointed up slightly. Ideally you want the pinion parallel with the front output of the t-case, so the similar ujoint angles cancel out any vibration.

 

[69jeepcj]

Your pinion looks ok to me in the photos. When they do a shcacle reversal you dont touch the spring perches on the axle itself, You swap the points where your spring attaches to the frame (spring hangers) around which does not change your pinion angle.

 

[PoliceMonkey161]

Hey...... That's a nice look'in CJ! What a great project Jeep. Photos can be deceiving, but the angle is no where near what I had imagined. It is in fact a Dana30 and the factory perches have not been altered- and that's good.

I looked at my CJ that I'm restoring as well as a separate D30 axle I have on the work bench and the angle is slightly positive above parallel more so when install with the leaf springs w/o a shackle reversal. But without putting a protractor on either I'm not sure of the exact angle?

You received some great input/feedback from other members. However I would tend to think that a shackle reversal would lower your opinion angle in a opposite manner that increased shackle length increases the angle?

 

[blaylock6502]

It looks to me like the shackles are longer than the brackets that attach the front end and if that is the case I would think the spring would set lower in the rear allowing the pinion to rotate downward.? Maybe not that's just the way it looks to me. Ill get the inclinometer out this afternoon!

 

[Bounty__Hunter]

Yep the shackle reversal is the problem. The rear spring eye is significantly lower than the front spring eye. A shackle reversal can be very bad if done poorly. For yours to be correct the rear shackle should attach to a sleeve through the frame. It's more labor intensive to do it correctly.

You likely have way too much caster as a result, which will require more steering input and increase wear on steering components.

 

[blaylock6502]

So does everyone agree I should start by putting it on the alignment rack and check caster??

 

[PoliceMonkey161]

If you have a inclinometer, you can measure it from the ball joint stud while on the garage floor level.

 

[blaylock6502]

Ill do that and update u!!

 

[Bounty__Hunter]

The correct fix would be to remove the shackle reversal or to move the upper shackle mount to a sleeve through the frame. You may also be able to move the front spring mount lower depending on your fab skills.

 

[69jeepcj]

Bounty, you do know that no cj spring mount gos through the frame like they do on yj,s? They all have hangers under the frame, unless what you are saying is going through the frame is part of a proper install. I dont have experience with reversals. I do know a lot of M38A1 jeeps came factory with shackle reversals.

 

[69jeepcj]

I couldnt edit my post, But I would not drill a hole in my frame to hang the shackle from. I have seen pics of many jeeps set up the way yours is.

 

[blaylock6502]

I tried to use the inclinometer yesterday and either I don't understand it (very possible) or its not an ordinary inclinometer. When it is level the needle points to 15 degrees. It is a General Motors special tool so it is likely it is made for another purpose. At any rate my 2 yr old and 2 month old twins have kept me tied up so as soon as I get a chance i will update u! Thanks!