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Oh, My Rear End

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KVH

KVH

Obi Wan
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Last week a replaced the gasket on the rear end/differential cover.

I did it carefully, used new bolts and washers.

I torqued the bolts as best I could.

I had a big puddle this morning.

All bolts were loose.

What did I do wrong? Loctite needed there, too??

Can I try it now, or once it leaks is the gasket and sealer shot?

thx
 
Sorry no help but I had simialr question. Rebuilt my rearend with a friend of mine, we let the sealer set for about an hour, torqued the bolts, and then next morning I had drips.

My question is, can I seal this effectively w/o the use of a new gasket? I know I will ruin it when I remove the cover and claen the surfaces. Next question, what is a good sealer to use for these surfaces?

Thanks,

Greg
 
People told me to use Hylomar, but that product isn't sold in my big city. There are several other Permatex products that should be just as good. One suggests waiting 12 hours before running the vehicle.

I'd think a new gasket is needed if you remove the cover.

Here's what I'm doing: Calling Harry at Moss Motors. He's great. The gasket they sold me is terribly thin and I wonder if that's part of the problem, though I also suspect Loctite would have been wise.
 
Kentvillehound said:
People told me to use Hylomar, but that product isn't sold in my big city.
Click to expand...


I never was a fan of Hylomar, but that doesn't make it a bad product. Hylomar works well when the two surfaces to be mated are machined to high tolerances and both surfaces are rigid. A cover on certain engine parts that can be distorted under torquing pressure will leak with Hylomar. I have found that Permatex Aviation works well if both sides of the gasket are coated liberally and the stuff is allowed to tack for at least 1/2 hour before being put together. Then use high-strength Locktite and quality bolts and lock washers to snug up. It would be best not to run it for at least a few hours. Hylomar might well be off the market. I have a new tube sitting in my tool drawer, cannot seem to find it at the local NAPA anymore.
 
Kentville: I had mine apart and back together
the next day. No leaks. Are positive lock
washers were installed?

Yes, yer gasket is ruined. Start over.
A very wise old guy here on the forum once suggested
I always purchase 2 of the cheapo gaskets in case
I mess up one.

Sure was good advice. I pass it on to you.
The Crypt Car eats gaskets like potato chips.

regrds,

Tinster
 
On the sprites rear end, I've been told to merely silicon it. To heck with the gskts.
 
Blue RTV will work fine in place of the original gasket.

Are you sure the replacement bolts have the same thread/ I've seen some cases where a PO had put 1/4" bolts into 5/16" holes...
 
For several years I managed a shop where among other things we rebuilt gear boxes for cheese making and other food prep equipment. Since people tend to not like gear lube in their cheese it was important that they did not leak - ever.

We used clear silicone and spread a thin coat on both sides of the gasket and the gear case and cover. We cleaned the metal surfaces with lacquer thinner before applying the silicone. Let them sit until tacky and assembled with only slight tension on the screws. After siting for an hour or so we then tightened the screws. 100's of gear boxes and no leaks - ever. We definitely found the clear silicone to be superior to any other type of sealant on the market.

One thing about applying the silicone - only a thin coat enough to cover with no gobs. That keeps it from squeezing out.

I first learned this when rebuilding a GM 350 diesel. They were notorious for leaking and the recommended sealants did not work so I tried the clear silicone. It worked great.

As for the lock washers, did you replace them. They loose tension and the grip edges wear.
 
New bolts and washers make me suspicious, NOT all bolts and washers are equal. You need to use the specific bolt and washer hardness required {Example #8 bolts} and the specific washer type also. Not all lock washers preform the same. Torque with a torque wrench, use the specific torque pattern {usualy a criss cross patern} and tightness {example 12 In lbs.} As for gasket sealer I use a thin coat of clear silicone on the gear housing and housing cover. Place the paper gasket on the cover over the silicone making sure the bolt holes are aligned. Let it sit of about 10 min then assemble the cover with gasket to the housing. Tighten to half of the torque setting let it sit for an hour then re-torque to the final tightness. After a day or two of use re- check the torque and tighten to specifications as needed.
Kerry
56 TR-3 TS 12909 L.O.
 
Paper gaskets are not the thing that seals. The paper acts as a vehicle for the sealant. It is better to use the paper gasket rather than no gasket at all. You will be more assured that the sealant is uniform.
 
Tom, you old codger! I'll bet that you also loved replacing that right side valve cover after the dummy owners never changed their oil and ended up cracking 2 or 3 of the aluminum rocker arm pivots. It was really a lot of fun on the Cutlass models with the diesel. Even more fun on the 442's with the 455.

Ah yes, I remember those good old Rocket 350/400/455 days like it was only yesterday.....
 
Brosky said:
Tom, you old codger! I'll bet that you also loved replacing that right side valve cover after the dummy owners never changed their oil and ended up cracking 2 or 3 of the aluminum rocker arm pivots. It was really a lot of fun on the Cutlass models with the diesel. Even more fun on the 442's with the 455.

Ah yes, I remember those good old Rocket 350/400/455 days like it was only yesterday.....
Click to expand...

Many times! /bcforum/images/%%GRAEMLIN_URL%%/grin.gif I loved those old olds motors. My first was a '55.
 
I was tipped off years ago by a local engine and race car builder to a product sold only thru and labled by CAT (Caterpillar). They have a gasket maker (don't know its secret ingredient) that never fully sets or cures but is useable immediately with no waiting. I have used this on everything from diffs, oil pans, transmissions, timing covers, etc. where I don't intend to routinely remove the piece like a valve cover. If you do have to remove the part/cover later, no problem, just wipe off the stuff and re-apply.

The stuff is very expensive ($14 for a little tube/bottle) but has been a staple of mine for years. It takes about half a tube to completely do a typical TR6 Engine and Transmission so a little goes a long way. You just apply a small beed on one of the parts just like other sealers and torque down. No waiting necessary as the stuff was spec'd by CAT to be used in the field by the mobile repair guys to get the machines back in use ASAP. I saw last year at NAPA that Permatex has a copy of the product (again, can't remember the name right now) so I bought a tube and tried on my M3 oil pan to compare as it was about half the price. NO JOY! Removed the pan and put the CAT stuff back on and once again no problems. I keep a tube of it in my tool box in the trunk and one back at the garage. Won't leave home without it.
 
Not sure what is going on with the loose bolts. What I do with tin covers like the diff cover or an oil pan is put a straight edge along the mating surface. Often the bolt hole area on the flange is warped. I place the flange on a piece of solid material and use a hammer to strighten the warp. Be careful not to bend the flange itself.
 
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