Quick pinion angle question

[crimsonride]

Hey guys. Just a quick dumb question. My rear driveline is short and in order to get a good pinion angle I need about a 30* angle on the pinion. Will this cause any issues with the axle, oiling etc? I need a beefier diff cover as well I guess.

 

[cjncustoms]

Hey guys. Just a quick dumb question. My rear driveline is short and in order to get a good pinion angle I need about a 30* angle on the pinion. Will this cause any issues with the axle, oiling etc? I need a beefier diff cover as well I guess.

You might run into pinion bearing oiling issues if your driving it around town a lot.

 

[I Lean]

You’ll might run into pinion bearing oiling issues if your driving it around town a lot.

This. You might relocate the diff breather to the top of the housing instead of the tube. Move (or add) a fill plug higher up on the cover. Those two things will help you overfill it the pumpkin, which will help that pinion bearing live. It will still likely have a short life though.

 

[crimsonride]

This. You might relocate the diff breather to the top of the housing instead of the tube. Move (or add) a fill plug higher up on the cover. Those two things will help you overfill it the pumpkin, which will help that pinion bearing live. It will still likely have a short life though.

Great advice. I will do both of those things. We'll see how it lasts.

Thanks guys. I burned them in so it's done. I'm curious what people are doing on wranglers with sprung over suspensions and these short drivelines. My last YJ was stretched so it wasn't much of an issue but this one is still close to the same wheel base. I think the new drive train has shortened the driveshaft distance some. ....Although, luckily enough my driveshaft appears to be a good length after all the modifications so I doubt I'll have to have it remade. ....I guess there is one thing that has actually worked out on this build that hasn't cost more money!

 

[AaronPaige]

Post how this works for ya I have always been told as a rule of thumb, keep the output angle and pinion angle as close as possible to avoid vibration issues, but if it works for ya run it.

 

[crimsonride]

Post how this works for ya I have always been told as a rule of thumb, keep the output angle and pinion angle as close as possible to avoid vibration issues, but if it works for ya run it.

That would be true for a standard driveshaft with U-joints on both ends. One with a CV joint however should have as little angle on the u-joint side and all the remaining angle on the CV side.

 

[Gravy]

I'm sure you've already done this, but make sure your pinion is a few degrees below straight on with the driveline to account for twist, especially with a leaf sprung rear.

You could fab a slinger for the pinion bearing (some guys who flip diffs do this) or run better seals at the center section, overfill and move your breather like the other guys have said.

 

[crimsonride]

I'm sure you've already done this, but make sure your pinion is a few degrees below straight on with the driveline to account for twist, especially with a leaf sprung rear.

You could fab a slinger for the pinion bearing (some guys who flip diffs do this) or run better seals at the center section, overfill and move your breather like the other guys have said.

Good advice. I will be rebuilding my track bar so it shouldn't have any wrap at all. I'll research how to make that slinger! I haven't decided what to do but I doubt I'll keep these axles very long. Just curious, what does relocating the breather do for you? Does it just put it higher so it doesn't spit oil?

 

[Gravy]

Good advice. I will be rebuilding my track bar so it shouldn't have any wrap at all. I'll research how to make that slinger! I haven't decided what to do but I doubt I'll keep these axles very long. Just curious, what does relocating the breather do for you? Does it just put it higher so it doesn't spit oil?

Even linked rears need the pinion a 2-3* below straight if they have a CV at the t-case and single joint at the pinion. The pinion will rise under torque even if you're running heims all the way around.

Relocating the breather does exactly that.
Also you can run a cup of ATF in the gear oil if you're overfilling to reducing foaming caused by overfilling.
Trail-Gear (among others) sells some triple lip style axle seals that mount in the housing. Circle track guys commonly use them in the 9" rears to keep the gear oil from filling the outside tube (when they continuously make left turns) and starving the R/P of oil.

 

[crimsonride]

Ahhhhhh....very good to know. Thanks!

 

[thenag]

Also you can run a cup of ATF in the gear oil if you're overfilling to reducing foaming caused by overfilling.
Trail-Gear (among others) sells some triple lip style axle seals that mount in the housing. Circle track guys commonly use them in the 9" rears to keep the gear oil from filling the outside tube (when they continuously make left turns) and starving the R/P of oil.

Wait... What...

When I put my ruff stuff diff cover on my 14 bolt I started having an issue of gear oil coming out of the breather... I was about to try synthetic oil... I think I will try that first...

Nathan

(sorry for the thread hijack...)

 

[Gravy]

Yeah. ATF is a detergent and prevents foaming, I think it works by lowering surface tension.