Leaking rear differential ford 9 inch

Save-A-Horse · Jul 3, 2012

I always had a small leak. Now it is a lot worse. Any thoughts on where to begin and what all I should replace? I've never tackled anything with the Diff before.

Save-A-Horse

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NGABronco · Jul 3, 2012

Hey Save-A, it might be the seal on the shaft, try to dry it off and see if it's coming from the front shaft??? That's an OK fix!! If it's coming from the diff seal then you got a major fix???%)%)%)

Kyle.malone · Jul 3, 2012

Can't really tell from the pics where the leak is coming from. Can you point a finger at the leak point and we can get you headed in the right direction.

Save-A-Horse · Jul 3, 2012

Okay, see this pic of the input of driveshaft into the 9" diff. It looks like it is leaking here.

xcntrk · Jul 3, 2012

Pinion seal. But you likely have a problem with pinion shaft play due to worn bearings causing the seal to leak. Can you grab the pinion yoke and feel slop or play?

broncnaz · Jul 3, 2012

X2 pinion seal
easy fix hopefully the pinion yoke is not grooved up from wear if it is you either need a new yoke or a speedi sleeve. As was said the pinion bearings may be worn as well. check condition of the outer one when you pull the seal. you should also get a new crush sleeve so you can get the correct preload when you retighten the pinion nut.

Save-A-Horse · Jul 4, 2012

In grabbing the yoke, I don't feel ANY play.
Maybe the seal is just aged and over time just became worse and worse?
Regardless, thanks for the info! Any tips on where to best find the parts, crush sleeve and pinion seal, etc... And should I consider looking at the transfer case seal too because there is small amounts leaking out there as well (but mostly it's near the rear diff). I really appreciate the feedback.

2wheelbob · Jul 4, 2012

I just did the pinion seal on my '74. I got the seal at NAPA and followed my neighbors directions (he's an old school mechanic and the smartest guy in the neighborhood). Just mark and measure everything before you start. As was mentioned above, you have to be careful not to over tighten the pinion yoke nut. If you over tighten it, you'll change the preload on the bearings and can cause them to fail. Take your time, pay attention to details (I marked the yoke, nut, and pinion shaft relations/measured the existing preload torque with a beam type torque wrench before and after replacing the seal/did NOT use any air powered tools or HAMMERS/used a homemade puller to help the yoke off the pinion shaft/and replaced everything in the exact same orientation as the start). I've got about 200 miles and so far so good.

69red · Jul 4, 2012

on the first pic it looks like there could be some leakage from around the vent/brake line block. check to see if your vent line is plugged. if it is plugged you could be pressuring up your diff and blowing oil out the seals.

broncnaz · Jul 4, 2012

Pretty much any parts store will/should have the seal and crush sleeve. basically if you replace the crush sleeve you should be able to just pull the yoke off replace the sleeve and seal and retorque you dont have to worry about marking anything. While I have reused crush sleeves I just dont recommend it. Removal torque is not the same as installation torque. rust dirt ect all effect removal torque and usually results in higher torque than required. But it can be done.

Save-A-Horse · Jul 5, 2012

Well the breather was clear. Time to go buy some parts!

Save-A-Horse · Jul 5, 2012

I also have the pinion gear out. Here it is, for your viewing pleasure. I think it looks overall in good shape.

Save-A-Horse · Jul 5, 2012

Save-A-Horse said:
I also have the pinion gear out. Here it is, for your viewing pleasure. I think it looks overall in good shape.

I can't seem to get the dang pinion retainer nut off. That's probably normal given how much torque it sees. Is that a job typically for an impact wrench? If it is, I will have to wait until my neighbor gets home before proceeding. %)

Timmy390 · Jul 5, 2012

Yep, Impact.

Put the pinion gear back in and then use a impact to take the nut off.

I'll get yelled at for this but here goes......you can reuse the crush sleve you just have to be easy when putting it back together. I've done it and know of others that have as well. You just have to be easy when putting the nut back on. You want to get it back in the same spot it was but no more. Even if you go a touch over it's OK as you have used bearing.

Inspect the yoke for groves. If you have a grove, get a speedy sleve or it will just leak again down the raod. I just put a sleve on my rear yoke. Got it at NAPA. Take the yoke with you as they will need to mesure it to get the right sleve. Heck, NAPA even installed mine for me right there at the parts counter.

You could also upgrade to a solid spacer and get rid of that crush sleve. You just mesure the overall size of the cursh sleve as it it now and then stack the spacers to the same measurement and torque the nut.

Tim

garberz · Jul 5, 2012

No need to reinstall to get the pinion nut off, just put the yoke in the vice and use a huge breaker bar to loosen, it's probably close to 200ft. lbs to loosen. I don't like the idea of using an impact gun around bearings, but for loosening, it's as much as a problem.

Save-A-Horse · Jul 5, 2012

I used my neighbor's impact tools with it installed and the sucker came off without too much of a problem. I replaced the seal and the "pinion bearing spacer" which I assume is the same thing as the 'crusher sleeve'. I did a little test drive w/ 2 qts of gear oil in it. It felt okay however I felt a little drag or slight vibration upon letting off the gas and coasting. I topped off the oil w/ another quart. I hope this job is done, still need to test drive it again.

garberz · Jul 5, 2012

When you put it back together using an impact gun, your basically guessing at the amount of preload your applying to the pinion bearings. You could very easily have them preloaded too much. You should change the seal with the pinion support removed, like you showed in post #12. Put the yoke in the vice and start crushing the new sleeve, after you take up all the play between the two bearings, hold the pinion support in the vice and check the amount of rotational drag. 18-23 in.lbs. it should be to rotate the pinion shaft.

Mark

Save-A-Horse · Jul 5, 2012

I should have stated this but I didn't use the impact to re-tighten. I used a torque wrench and had it set at 175 ft-lbs. which should be spec. I simply don't have a good work bench, strong enough to use a vice at this torque, so I did it installed.

Save-A-Horse · Jul 6, 2012

Well, everything is back together and there is no more leak! I may have a new problem though... when I let off the gas, and coast, it seems to have a feeling of slight vibration and a little drag. When I put it into Neutral the vibration goes away. I am thinking I may need to change out the u-joints now.

Jay1clarke · Jul 11, 2012

RE: Crush Collar

Timmy390 said:
Yep, Impact.

Put the pinion gear back in and then use a impact to take the nut off.

I'll get yelled at for this but here goes......you can reuse the crush sleve you just have to be easy when putting it back together. I've done it and know of others that have as well. You just have to be easy when putting the nut back on. You want to get it back in the same spot it was but no more. Even if you go a touch over it's OK as you have used bearing.

Inspect the yoke for groves. If you have a grove, get a speedy sleve or it will just leak again down the raod. I just put a sleve on my rear yoke. Got it at NAPA. Take the yoke with you as they will need to mesure it to get the right sleve. Heck, NAPA even installed mine for me right there at the parts counter.

You could also upgrade to a solid spacer and get rid of that crush sleve. You just mesure the overall size of the cursh sleve as it it now and then stack the spacers to the same measurement and torque the nut.

Tim

Im not going to yell about the crush sleeve, but I tried it with no luck and got a leak again. After doing this a few times I had someone machine me a solid collar (like to one on a dana 44), $10.00 later I have a rearend that I can change the seal on and never worry about a leaking colar.

Leaking rear differential ford 9 inch

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