M1009 Replacing Rear Driveshaft/Differential seal

[Mike_Pop]

Everything seems to be fine, very little play in the shaft, bearings look good. I've got the seal back in and driveshaft on and going to take it for a test spin to see if there is leakage. I honestly don't think it is anything too serious except a leaking seal. The truck sat a while before I bought it and it's been slowly leaking ever since I've driven it for the past 30K miles. I surely could have driven it with a leaking seal but I thought I would do the maintenance before my trip.

To answer your question Chris, the flange is well secured to the yoke and has not moved. The whole yoke assembly moves with the rotation of the driveshaft so I'm guessing that there should be some sort of a gap to prevent wear on the flange. I just didn't know how much of a gap and having someone look at their M1009 would have been the most help.

 

[Bozor1000]

Mike, check this website for help if you need anymore help with it. www.4x4mecca.com

 

[Mike_Pop]

Ok...I took the truck for a test spin, no leaks. However, I'm still not happy with the gap issue. Everything is seated as tight as can be. There isn't a lot of play in the shaft coming out of the differential yet I still can't manage to get the yoke to seat deepr on the shaft.

Taking the yoke off was easy. I unscrewed the nut and it pulled right off. I didn't have to beat it off nor did I feel the shaft move out at all.

 

[FMJ]

Mike, that really looks okay to me.....As long as the nut is tight and won't back off, you should be fine. BTW If anything, the shaft will move back into the housing when the nut is removed.

 

[Mike_Pop]

FMJ:

There is nothing holding the seal in place except friction...correct? Seems like the nut really only holds the yoke on the shaft.

 

[FMJ]

Correct on both questions, you did have to drive the seal into the housing with a seal driver, or hammer correct? It didn't just drop into place in the hole?

 

[Mike_Pop]

Yes, I used a pointed hammer and made sure I nicked it up real good with holes and scores around the sides.

To quote the song, "Wet Dream":
My mechanic had told me that I'd blown a seal. I said fix the damn thing and leave my personal life out of it.

 

[FMJ]

Perfect!

you should be fine!

 

[Mike_Pop]

By the way, the larger seal pictured above will not fit. The inside diameter is too big. However, the outer diameter is the exact same size as the yoke so I would imagine it offers a better seal agains the yoke. The larger seal is for the 14 bolt rear but being that the parts store is 80 miles away, I got both seals just in case.

 

[FMJ]

The only thing I would do myself is lightly center punch the pinion nut near the threads on the pinion for extra insurance that the nut does not back off. But its up to you. I believe the nuts are shouldered/tapered and are single use items, on once, off once, but that never stopped me from reusing them once.

 

[steelsoldiers]

Yep, the "paint" on the outside of most seals will heat up from the friction of being driven into the bore and it helps to seal everything together. Did you put some red Loctite on the pinion nut? I would recommend that.

I wish I had my 1009 to measure for you. That seal gap looks good to me. Have a safe trip.

 

[ida34]

The preload is usually measured in inch pounds not foot pounds. I have a beam type inch pound torque wrench. You put it on the pinion nut and see how many inch pounds it takes to spin the pinion. You have to have the diff carrier taken out so that the pinion does not have the extra drag of the ring gear. You basically have to tear it apart totally. That being said I have just replaced the seal before and tightened the pinion nut but now that I am older I would probably take it all apart to do it right. Most of this is not in Chilton manuals. It is considered a professional only task and just like rebuilding an auto transmission they just do not cover it. Be careful about trying to get it tighter. You will compress the crush sleeve more and will have to much a preload on the pinion bearing. It will be just fine for a while until the bearing fries. The gap looks ok to me.