Changing out the front pinion seal on a 58 Chevy.

Hi,

I've read in a couple of posts that you just whip of the nut and replace the seal. Just wanted to get a little more information before I dig into this.

Here's what the manual says, let me know what I can ignore, and what I can't.

1. Raise one rear corner of the vehicle off floor and place jack stand under frame rail. Note: This is to lock one rear wheel and obtain differential to body clearance. If operation is to be performed on a hoist, support frame on stand jacks, allow axle to drop for clearance and expand brake shoes on one wheel to lock wheel.
2. Check free wheel for freedom of rotation
3. Seperate rear universal joint, tape trunnion bearings to joint and support rear of propellor shaft.
4. Using tool J-5853 on the companion flange nut, rotate the pinion through several complete revolutions and record the torque required to keep the pinion turning. If old flange is to be installed, mark pinion and flange for reassembly in the same relative position.
5. Holding drive flange with tool J-2637, remove companion flange nut and special washer. Discard nut.
6. Remove drive flange using tool J-0820 bolted over holding toll-2637. Pry old oil seal out, using a screwdriver or hammer and chisel.
7. Inspect drive flange for smooth oil seal surface or worn drive splines. Replace if necessary.
8. On new flanges or old flanges with damaged deflectors,install new deflector, using tool j-5749.
9. Soak new seal in light engine oil for 10 minutes before installation, wipe O.D. of seal and coat O.D. of seal with a sealer, such as G.M. Sealing Compound. Install new oil seal using tool j-5154
10. Install drive flange, aligning marks on pinion and flange if old flange is being used. If flange does not go on shaft easily, pull flange on shaft, using tool j-5780. The tool is threaded onto pinion shaft and large nut tightened to pull flange on shaft. Remove tool and install special washer and a new self-locking nut. CAUTION: Do not hammer flange on pinion shaft. To do so will damage ring gear and pinion. Tighten nut to remove end play and continue alternately tightening in small increments and checkingpreload torque with inch pound torque wrench until it is the same as recorded in step 4. NOTE: The position of the pinion and flange was previously marked so that reinstallation may be made with flange and pinion in same relative position
11. Readjust brake if expanded above.
12. Lower vehicle to floor and road test for leaks and noise.

So, do I really need all those special tools?

Thanks for any help.

 

You can make a flange holding tool pretty easily from a piece of 1/4" x 2" bar stock, and you probably can just tap the yoke back on without hurting anything (the splines are usually pretty loose after 50 yeasr). you can use a normal two jaw puller to get the yoke off. you can measure torque with an inch pound torque wrench and the necessary adapter to put the 1-1/8" or whatever it is socket on it. You can use an appropriate sized piece of pipe or big deepwell socket to install the seal, or maybe even a 4x4 wood block with a hole drilled in it to clear the pinion stem.

So no, you don't need all those specific special tools, but you do need some relatively specialized tools to do rearend work.

 

Thanks,

Those are the kind of things that I was thinking, but wanted to know if anyone else had done it that way with out loosing the pinion flange at 70 mph going down the highway.

Thanks again.

 

I helped a freind change the pinion seal on his '58 Chevy wagon a while back. As we removed the nut from the pinion, we marked it's position and counted the number of turns it took to come off. We removed the yolk and the old seal, installed the new seal and placed the yolk back on the pinion (it went back on with no trouble). We then replaced the nut and tightened it the exact number of turns that we counted when we removed it and made sure position marks lined up. That's it. The rear end has been leak and trouble for about 3 years now.

 

There are different ways to approach this...usually the crush sleeve is worn out by the time the seal wears out, so ideally you would take the sleeve out and replace it too, then reset the pinion preload to where it should be, but that kind of requires pulling the axles, third member, and differential. Or you can put the yoke and nut back where they were, and hope for the best, most of the time it will indeed last for several years.

If you're the type of guy that likes to make sure things are right, take the whole thing apart and check all the bearings and check the pinion gear for cracked teeth (common on old GM rears) etc.

 

squirrel,

I've got a 500 mile trip planned at the end of the month, so I'm thinking I'm checking the pressure relief cap, changing out the seal and praying.
Maybe when I get back I'll investigate the entire rebuild. Thanks for the help.

 

Mike,
Hopefully all goes as well with mine.
Thanks for the tip.

 

I just finished doing this on my 59. It is indeed a 1 1/8 size nut... the one size I didn't have. I love an excuse to buy a new tool! I used a foot-pound torque wrench, but the yoke spun so easily that it wouldn't even register, so I marked the nut and yoke and counted the number of turns it took to remove the nut (9 for me) and put it back on using exactly 9 turns. Hopefully it will work. I was alos advised to put some Permatex or other sealant on the washer and nut, but I also put some around the new seal, just in case.

 

I put permatex around the outside of the seal, and rtv or permatex on the nut, washer, and maybe the threads. Although you need to put loctite on the threads if it's loose like that!

 

oops, actually the place I try to get the sealer is on the yoke splines, then the threads and washer really don't need.

 

A few days late, but here's my little bit; as long the only complaint was a pinion drip and you get the pinion preloaded exactly as before, then the ring and pinion set-up should be as before. This is what the shop manual is striving for. In my opinion, the unit should still have a lot of life in it as long as you don't just try to break it! These units were used behind 409's, and I had one from a '64 w/posi(the case has a "P" cast in it!) and I managed to break an axle one nite with a 350 in my '55. So just get the nut back where it was, forget the inch pound stuff, you mark the nut and shaft and can tell by feel that you are right, then use a center punch and stake the damn thing so it don't come off! Hey, it's either gonna Go or Blow anyway. I've got several posi units and would use up old 3rd members, but first I'd convert them to posi, never bought any parts but a gasket and a seal. Ran the hell out of 'em too! I do

 

been doing it the way unclee says for 35 years,off and on.use a big pipe wrench to hold pinion,and used a exhaust flange with about 4 inches off pipe on it to drive seal in.pinion fits inside of it. pretty much all the above will work fine. take time counting when takin it off and all should be ok. go for it.

 

Ditto. I make my mark by buzzing a cutoff wheel across the pinion nut and the the couple or so threads that are showing. Clean, and Loctite the threads

 

So do they have a crush sleeve like a 9 inch? Sometimes a couple shims to get a little fresh crush helps on old tire 9 inchers. I have heard of guys setting them up without a crush sleeve and doing it all with a spacer and shims.
I don't think you could change the pinion to ring gear relationship, all the precautions are to maintain bearing preload.

 

Loctite is your friend.

 

New crush sleeve for the 55-64 chevy rears is available from Summit, it's Ratech 3110, I have one sitting here in front of me in the baggie....they are not very expensive....