[dfwjr1973]

Hello,

For our EV conversion, I will be cleaning up the existing stock drivetrain and only replacing things that are really worn out or are safety critical (like the brakes).

Now that we have the Jeep on it's side, I can see what looks like leaky seals on both the front and rear differential. Both feel really smooth when spun by hand and I can easily spin both wheels. Just seems like the seals or gasket is leaking.

Below are some pics.

What are your suggestions? I was thinking to just clean the exterior of the diff and axles, remove the covers and reseal with new gaskets. Or do you think a complete rebuild is necessary?

BTW...there is a hose with a plastic "screw" inside...on both...that looks like some kind of breather... What is that? Sorry for the newbie question...

 

[Shark_13]

Looks like you have a leaking pinion seal.

The rubber hose is a vent.

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[steves92]

EV conversion?! Do you have a build post? Curious as to what’s involved.


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[dfwjr1973]

EV conversion?! Do you have a build post? Curious as to what’s involved.

1999 TJ EV Conversion

This is the build thread for my wife's 1999 Jeep Wrangler Sahara. I am sure there is a mix of love and hate for this from forum members as we are converting it to electric. My wife grew up in Austria and her favorite show growing up was Gilmore Girls and she had a dream of one day owning the...

www.wranglerforum.com

 

[dfwjr1973]

Looks like you have a leaking pinion seal.

The rubber hose is a vent.

Thanks. To fix this, what do you suggest? Is this a major rebuild or something simple?

 

[Shark_13]

Thanks. To fix this, what do you suggest? Is this a major rebuild or something simple?

Search for a YouTube video, they are easy.

You should replace the pinion nut if possible, but some will add blue loctite and no issues. You should put it back on the same tightness as the old one though.

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[steves92]

This is awesome. can’t wait to see the transformation.


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[Mattaeus]

Looks like you have a leaking pinion seal.

Yup, that's really the only issue we can see here. Have you popped the differential covers off to inspect the gears? You could also remove the carriers to inspect the bearings. At that point, might as well replace the inner axle seals for the front axle. The rear axle seals are part of the axle shaft assembly rather than pressed into the axle tubes. The rear seals and bearings are easy to replace, as long as you have a shop press. This Jeep has a Dana 44 rear, right?

The pinion seals are very easy to replace as well. Though you will need a high torque impact wrench or a long breaker bar to remove the pinion put. The pinion nut torque spec is 200 ft-#. Also, you will need something to hold the pinion in place while removing and fastening the nut. Some folks like a big pipe wrench. I use a long piece of 1" angle with two drilled holes for the U joint strap bolts.

 

[dfwjr1973]

Search for a YouTube video, they are easy.

Yep...just searched and watched a few. Piece of cake. Thanks!

 

[dfwjr1973]

Yup, that's really the only issue we can see here. Have you popped the differential covers off to inspect the gears? You could also remove the carriers to inspect the bearings. At that point, might as well replace the inner axle seals for the front axle. The rear axle seals are part of the axle shaft assembly rather than pressed into the axle tubes. The rear seals and bearings are easy to replace, as long as you have a shop press. This Jeep has a Dana 44 rear, right?

The pinion seals are very easy to replace as well. Though you will need a high torque impact wrench or a long breaker bar to remove the pinion put. The pinion nut torque spec is 200 ft-#. Also, you will need something to hold the pinion in place while removing and fastening the nut. Some folks like a big pipe wrench. I use a long piece of 1" angle with two drilled holes for the U joint strap bolts.

Thanks for the info! We just bought the Jeep used a few months ago and the new owner had no idea what has been done. I haven't cleaned off the diff cases yet enough to see the ratios or models yet... Like you suggested...once I started down the route of opening up the diff I was thinking to just rebuild the whole thing... But now I am leaning towards getting the EV running and then if we grenade the diffs with the extra torque going through them (even though I can control the torque application rate via software), then time to upgrade... We will be putting 1500Nm peak (675Nm cont.) through the diffs at 730A (300A cont.) & 400+VDC... Of course in 4WD Low...it will be almost another 3x that... Should be fun.

 

[Mattaeus]

I noticed the pictures of your axles in an earlier post. That's a Dana 35 rear axle. You may want to look into making that unit stronger. You're saying that the powertrain can make 1100 Ft.# of torque? Dana 35 is not the axle for that amount of power. That axle has C-Clip axle shafts. If an axle shaft breaks, it can be ejected from the housing along with the wheel assembly.

 

[dfwjr1973]

I noticed the pictures of your axles in an earlier post. That's a Dana 35 rear axle. You may want to look into making that unit stronger. You're saying that the powertrain can make 1100 Ft.# of torque? Dana 35 is not the axle for that amount of power. That axle has C-Clip axle shafts. If an axle shaft breaks, it can be ejected from the housing along with the wheel assembly.

I completely agree with you...if we were taking this off-roading or racing or climbing huge hills. But this is mostly a daily driver for my wife around town and a "training" tool for her EV education program. So, even though the powertrain can make that power, it will very rarely, if ever, be stressing the drivetrain with that torque. Remember, to produce torque you the other end resisting the rotation...

 

[Shorthood]

If it was my rig, I would make sure the vent tube are clear. Then clean everything up and drive it for a while and see how bad it leaks. You would be surprised how oven a gearbox will leak on equipment because of pressur