HP Dana 30 Gear Pattern Check

UKTJ · Oct 3, 2024

I know there was another thread on this already this week, but don't want to hijack that one. My backlash is at 0.008". My patterns on first run:

Drive Side

Coast Side

I'm looking at it with my totally untrained eye and saying pinion too deep, do others agree? If so, any thoughts on reduction in shims likely to be required?

I took a gamble and put the original slinger on there with just the baffle and no additional shims, so if I need to reduce depth I will need to pull the bearing (I have a clam shell puller) and reinstall with no slinger but add shims.

hosejockey61 · Oct 3, 2024

UKTJ said:
I know there was another thread on this already this week, but don't want to hijack that one. My backlash is at 0.008". My patterns on first run:

I'm looking at it with my totally untrained eye and saying pinion too deep, do others agree? If so, any thoughts on reduction in shims likely to be required?

I took a gamble and put the original slinger on there with just the baffle and no additional shims, so if I need to reduce depth I will need to pull the bearing (I have a clam shell puller) and reinstall with no slinger but add shims.

I know you aren't going to want to hear this......but I think you might be there! Remind me which axle this is, front/rear. It looks good but I can't tell 100% because there is too much paint at the root so I can't see if it's truly deep or not. Wipe that paint off and only apply enough to turn it yellow. More is not better. Just enough to make it yellow. Can you see the bulge of paint I'm talking about? I'm pretty certain you are good to go but repaint it so we can verify. Way to stick with it through all the frustration.

Woodrow · Oct 3, 2024

hosejockey61 said:
I know you aren't going to want to hear this......but I think you might be there! Remind me which axle this is, front/rear. It looks good but I can't tell 100% because there is too much paint at the root so I can't see if it's truly deep or not. Wipe that paint off and only apply enough to turn it yellow. More is not better. Just enough to make it yellow. Can you see the bulge of paint I'm talking about? I'm pretty certain you are good to go but repaint it so we can verify. Way to stick with it through all the frustration.

HP 30, so front. I agree. Probably good but let’s see it with less paint.

tplasek · Oct 3, 2024

This looks very close to me. I don't like the ridge of paint down low, but I think it may be access paint. If you were to lessen the pinion depth, I think the pattern would move to heavily towards the top of the tooth.

If the marking compound it too thick, you can thin it out with a small amount of gear oil

UKTJ · Oct 4, 2024

hosejockey61 said:
I know you aren't going to want to hear this......but I think you might be there! Remind me which axle this is, front/rear. It looks good but I can't tell 100% because there is too much paint at the root so I can't see if it's truly deep or not. Wipe that paint off and only apply enough to turn it yellow. More is not better. Just enough to make it yellow. Can you see the bulge of paint I'm talking about? I'm pretty certain you are good to go but repaint it so we can verify.

It's a HP Dana 30 for the front.Fingers crossed, ran it again with less paint. I still wonder if it looks a little deep. But getting it shallower will be a hassle as I need to pull that slinger, so hoping it is good enough, rather than chasing perfection.

Drive Side

Coast Side

hosejockey61 said:
Way to stick with it through all the frustration.

Thank you for that, but I could not have got to this point without the support of a number of really helpful people on this site and your superb YouTube content. There is a lot of crap going on in the world, but when people take the time to help out a complete stranger from thousands of miles away it goes a long way to restoring my faith in humanity. Thanks guys!

But not to forget I still have a way to go. I still have to take on the part that I am most hesitant about, drilling the housing to get the copper tube into the bulkhead fitting - I am completely paranoid about breaking that copper line off the seal housing. Oh, and then there is the matter of doing it all again on the rear Dana 44.

Blackjack · Oct 4, 2024

Thin out you marking compound a touch. You are the tiniest bit deep.

hosejockey61 · Oct 4, 2024

So in the predicament you are in, here are your options (and I know you are tired of this thing lol). As blackjack stated, you are ever so slightly deep.... Maybe 1 or 2 thou at the most. You can try to chase perfection as you say or you can run it as is. I always try to get the best possible pattern. In this case, it's your front axle which doesn't see the same load as the rear and it's running passively unless you are in 4x4.

If you are truly over this project, you will most likely get away with running it as is and not experience any issues. But there's also the chance that you might experience something, either a small vibe or noise.

I'm always an advocate for the best possible pattern but ultimately the decision is yours. Worst case scenario is that you now know how to set up gears if you need to do it again.

hosejockey61 · Oct 4, 2024

hosejockey61 said:
Remind me which axle this is, front/rear.

Woodrow said:
HP 30, so front.

This happens to me all the time lol. The thread title says it all but I get locked into the post and feel like a dipshit when I figure it out

.

I get so many request for pattern interpretations that they all start running together and looking the same.

UKTJ · Oct 4, 2024

hosejockey61 said:
So in the predicament you are in, here are your options (and I know you are tired of this thing lol). As blackjack stated, you are ever so slightly deep.... Maybe 1 or 2 thou at the most. You can try to chase perfection as you say or you can run it as is. I always try to get the best possible pattern. In this case, it's your front axle which doesn't see the same load as the rear and it's running passively unless you are in 4x4.

If you are truly over this project, you will most likely get away with running it as is and not experience any issues. But there's also the chance that you might experience something, either a small vibe or noise.

I'm always an advocate for the best possible pattern but ultimately the decision is yours. Worst case scenario is that you now know how to set up gears if you need to do it again.

Currently I have no shims setting depth, just the original slinger and the new baffle. The original slinger was 0.062". I think I am going to try for a better pattern by pulling the bearing off, removing the slinger, repressing the bearing and then using shims behind the baffle to do that. While, as you say, it is the front axle, in the conditions in the UK it is not uncommon to be spinning a lifted wheel pretty quickly and then to 'grab' traction, so the front can see a fair bit of load. Ordering new gears and having them ship to the UK is costly and not quick, so I'd rather do all I can at this stage to limit the risk of having to regear again any time soon. The only thing that could change my mind is if I measure the shims provided by Revolution on the install kit and find there is not a combination that gets me to both 0.060" and 0.061", if that is the case I can't improve things with the shims I have any way.

Thanks again to you and @Blackjack for the further input.

hosejockey61 · Oct 4, 2024

UKTJ said:
Currently I have no shims setting depth, just the original slinger and the new baffle. The original slinger was 0.062". I think I am going to try for a better pattern by pulling the bearing off, removing the slinger, repressing the bearing and then using shims behind the baffle to do that. While, as you say, it is the front axle, in the conditions in the UK it is not uncommon to be spinning a lifted wheel pretty quickly and then to 'grab' traction, so the front can see a fair bit of load. Ordering new gears and having them ship to the UK is costly and not quick, so I'd rather do all I can at this stage to limit the risk of having to regear again any time soon. The only thing that could change my mind is if I measure the shims provided by Revolution on the install kit and find there is not a combination that gets me to both 0.060" and 0.061", if that is the case I can't improve things with the shims I have any way.

Thanks again to you and @Blackjack for the further input.

Measure your songs BEFORE you pop the bearing off!

Apparition · Oct 4, 2024

hosejockey61 said:
Measure your songs BEFORE you pop the bearing off!

shims?

UKTJ · Oct 4, 2024

hosejockey61 said:
Measure your songs BEFORE you pop the bearing off!

Unless my maths has let me down the shims will allow me to get to 0.060" and 0.061". A heavy bias to even number shims, but I have two 0.015" shims, and I can combine that with others to get tp 0.061".
As it is Saturday tomorrow will be having a good run at it. I should get the pinion depth sorted and can then move on to the pinion pre-load. I am hoping I will also be able to get to pulling it all out and drilling the hole for the bulkhead fitting. Fingers crossed.

hosejockey61 · Oct 4, 2024

And I can't remember from your other thread....is your setup race new or used? Same brand?

UKTJ · Oct 4, 2024

hosejockey61 said:
And I can't remember from your other thread....is your setup race new or used? Same brand?

Brand new and same brand - Timken. I remembered the thread from the guy from Riga that got caught out by that if I remember correctly.

Blackjack · Oct 4, 2024

What you need to use some shims is a standard slinger. Yours most likely was the type that was the shim as that is how Dana started doing it later on to decrease setup time during production. That being said that pattern would run especially being a front diff.

UKTJ · Oct 5, 2024

I have removed the slinger (which as @Blackjack rightly says was the shim as well). I'm relying on the prior explanation by @hosejockey61 about why a slinger is not required, as I do not have a thinner after market one, Revolution do not prvide one in their kits.

I may be becoming a bit obsessive at this stage as I have started to measure shims to 0.0000". I was finding that a shim I was calling 0.012" could be anything from 0.0116" to 0.0124", when I am only chasing 1 or 2 thousandths I can't rely on offsetting variability. The pattern below was run with the slinger removed (which I double checked and did read 0.062". I used a shim pack that totalled 0.0596", so a reduction in pinion depth of slightly more than 2 thousandths. Once everything was reinstalled the backlash had increased from 0.008" to 0.010", but I believe this is still at the limit of the Revolution specification of 0.006 - 0.010" (this makes sense to me as if I have got it right the pinion has moved very slightly further away from the ring gear).

I am not convinced that my untrained eye can see a massive difference in the resulting pattern, but I think it looks very marginally better in terms of centring between root and crown. I think if I take any more out of the pinion depth the pattern will end up beyond the face of the tooth. Meanwhile the slight increase in backlash has resulted in the pattern being a little better centred between the heel and toe.

Drive Side

Coast Side (I think I went too far with reducing the amount of paint here, but the pattern is just about visible on one of the teeth)

Any thoughts?

I'm hoping I am good and I am going to move on to the pinion pre-load now. But if I am reading the pattern wrongly that shouldn't stop me going back to depth and backlash.

hosejockey61 · Oct 5, 2024

UKTJ said:
I have removed the slinger (which as @Blackjack rightly says was the shim as well). I'm relying on the prior explanation by @hosejockey61 about why a slinger is not required, as I do not have a thinner after market one, Revolution do not prvide one in their kits.

I may be becoming a bit obsessive at this stage as I have started to measure shims to 0.0000". I was finding that a shim I was calling 0.012" could be anything from 0.0116" to 0.0124", when I am only chasing 1 or 2 thousandths I can't rely on offsetting variability. The pattern below was run with the slinger removed (which I double checked and did read 0.062". I used a shim pack that totalled 0.0596", so a reduction in pinion depth of slightly more than 2 thousandths. Once everything was reinstalled the backlash had increased from 0.008" to 0.010", but I believe this is still at the limit of the Revolution specification of 0.006 - 0.010" (this makes sense to me as if I have got it right the pinion has moved very slightly further away from the ring gear).

I am not convinced that my untrained eye can see a massive difference in the resulting pattern, but I think it looks very marginally better in terms of centring between root and crown. I think if I take any more out of the pinion depth the pattern will end up beyond the face of the tooth. Meanwhile the slight increase in backlash has resulted in the pattern being a little better centred between the heel and toe.

Drive Side

View attachment 563381

Coast Side (I think I went too far with reducing the amount of paint here, but the pattern is just about visible on one of the teeth)

View attachment 563382

Any thoughts?

I'm hoping I am good and I am going to move on to the pinion pre-load now. But if I am reading the pattern wrongly that shouldn't stop me going back to depth and backlash.

Welcome to gear setting! You will often see shims that vary like that. It's not the specific exact number you're looking for, rather are you making the shim stack thicker or thinner until your pattern looks good. I have to change out the same "thickness" shim before to get where I wanted it.

With that said, I would run what you have

sierradmax · Oct 5, 2024

Pattern looks good. I'd run it. For a HP front axle, put the jeep on jackstands and run in reverse (with oil) for a few minutes. Let the ring gear sling oil up into the HP passages before taking it on the street.

Blackjack · Oct 5, 2024

On high pinion diffs I would not run without the baffles or slinger as they help keep the pinion bearing bathed in oil. Low pinion diffs the pinion is submerged for the most part so baffles and slinger as not as necessary.

HP Dana 30 Gear Pattern Check

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