tips/ tricks needed for sealing a pinion flange

avbcon12

avbcon12

Club Member
i replaced my pinion seal last year and it still leaks. it has a ford racing 3.55 gear in the stock 8.8 housing. any helps is appreciated. i thought it might just need to be driven to swell the seal but since i dont really drive my car thats kinda hard to do, haha. i have driven it about 3-400 miles sine i replaced it.
 
If it didn't seal up the first time then it won't unless you use something to swell the seal... But I wouldn't recommend that since that could go anytime really... It should be replaced...
 
thats what im getting at, whats the best way to replace it? because what i did before didnt work. i just removed the pinion nut, removed the flange, replaced the seal, tightened the nut down to no slop (or no more than was there prior) in the pinion to ring gear tolerances.
 
Replace it again but this time when your putting the seal in... Make sure you take some oil/rear end dope/trans fluid or something to lubricate the seal while installing it... A lot of times it gets a little nick or tear in it and that's the causing of the leak...
 
yeak like ReiKo said, make sure you lube the lip on the seal, and make sure the sealing surface on the flange is clean and free of burrs.

If your next seal leaks too, you have a pinion bearing problem
 
yeah i know the crush sleeve should be replaced everytime but i didnt have time and nobody had one when i was doing it so it was left in.

ill try it once again, if it leaks again i guess ill send the rear end in to get built.
 
im in west bloomfield to man. i got my sleeve at rider racing in taylor... on my way home from work. like said above... the correct way to do it is to put a brand new sleeve in it and tighten it to i believe 15-20 inch lbs of drag on it with axles out spin the nut with an torque wrench. i know that isnt what you asked for but just in case you didnt know...

as far as the seal... get a brand new seal, put some rtv black... or other silicone based sealer... on the new seal. not the face of course just the part that will slide into your housing. and then drive her home with a rubber mallet. make sure your put some oil on the lip of the seal like said above so your pinion shaft wont tear it when its installed.
good luck with it.
 
Ding ding ding! the winner goes to Tom prostreet377

he reminded me that i forgot the RTV the splines of the flange/pinion gear!!!!!! thats where the oil is leaking from now that i think about it, its not dripping down on the rear end as much as its being flung all over my mufflers and torque arm
 
tightening the pinion down to the correct spec is difficult if not nearly impossible to get correctly. if you already have done it once, i don't think i would recommend doing it again. leave it alone and deal with the seepage if you can. placing silicone on the washer or flange of the pinion nut will seal the splines, along with using loctite on the threads will also help prevent the pinion from loosing.
if this was the first time for removing the nut, i would recommend using a punch and making several marks on the pinion nut and pinion shaft, to tell how far it was previously tightened. make the pinion nut just slightly tighter. too loose, you will wreck your ring & pinion, and too tight you will prematurely wear out your pinion bearings.

back in the early 80's i worked in a shop that only repaired rear/front driving axles. back then we would charge 80-100 bucks to replace a pinion seal on a vehicle. I told the owner he was nuts. any gas station around would do that job for 25-30 bucks.
His reply was I know, that's wonderful!.....I soon learned why he was so happy...above 90% of the vehicles that came in for a pinion seal and left, were always back in 3-6 months with bad pinion bearings, always from someone improperly tightening them.
good luck.
 
Detroit Gearbox said:
tightening the pinion down to the correct spec is difficult if not nearly impossible to get correctly. if you already have done it once, i don't think i would recommend doing it again. leave it alone and deal with the seepage if you can. placing silicone on the washer or flange of the pinion nut will seal the splines, along with using loctite on the threads will also help prevent the pinion from loosing.
if this was the first time for removing the nut, i would recommend using a punch and making several marks on the pinion nut and pinion shaft, to tell how far it was previously tightened. make the pinion nut just slightly tighter. too loose, you will wreck your ring & pinion, and too tight you will prematurely wear out your pinion bearings.

back in the early 80's i worked in a shop that only repaired rear/front driving axles. back then we would charge 80-100 bucks to replace a pinion seal on a vehicle. I told the owner he was nuts. any gas station around would do that job for 25-30 bucks.
His reply was I know, that's wonderful!.....I soon learned why he was so happy...above 90% of the vehicles that came in for a pinion seal and left, were always back in 3-6 months with bad pinion bearings, always from someone improperly tightening them.
good luck.
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Thats what I thought... I had to do a write up on that crap for a class i took. We used break away specs on the nuts then re-installed them to what the break away was and 60% of them would match the backlash/ rotational tq value check prior to removal the rest were junk...


That things gunna be doing the howl doggy
 
again, when i did it the first time i checked and rechecked the specs on the pinion to ring gear tolerances. im well aware that im supposed to change the crush sleeve each time but didnt do it last time do to not being able to find one. the rear end is just fine now, especially because i dimpled the nut/pinion like you said..

im not looking forward to doing it again since i have to remove the entire torque arm. but since im doing this im also going to throw in the lakewood bell and new clutch too.
 
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avbcon12 said:
again, when i did it the first time i checked and rechecked the specs on the pinion to ring gear tolerances. .
Click to expand...

tighten the nut as tight as you can, it makes no changes to backlash at all.
checking pinion to ring gear tolerances has nothing to do with pinion preload.
pinion preload is what your disturbing by removing the nut. setting proper pinion preload requires a solid spacer or a new crush sleeve.
checking pinion preload properly, cannot be performed with the carrier in place. so unless your going through the troubles of removing your axle shafts and carrier and using a inch pound torque wrench to check rotating preload of the pinion.

if your having a hard time understanding the concept, try imagining overtightening a front wheel bearing (old school front wheel bearing with two tapered roller bearings) you tighten them with a wrench, back it off, make it "finger tight", check end play and place a cotter pin to prevent the nut from backing off what happens when you over tighten the nut?

the crush sleeve serves as a spacer that allows you to adjust the space between the bearings. using a new crush sleeve requires you to tighten the nut very tight. this process keeps the nut from backing off (hence no cotter pin).

my advise,(and i have done a few thousand in my life time, I'm only trying to give you accurate advise) live with the seepage, unless its dripping and leaving a puddle.
 
igotaneed4speed said:
Thats what I thought... I had to do a write up on that crap for a class i took. We used break away specs on the nuts then re-installed them to what the break away was and 60% of them would match the backlash/ rotational tq value check prior to removal the rest were junk...


That things gunna be doing the howl doggy
Click to expand...


breakaway as in Torque to tighten or loosen??
 
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