The Stovebolt Site Forums The Shop Area Driveline Diff leaking after 3.55 R & P swap

After having the parts sitting here for a few years, I finally found a shop willing to do the R & P swap on the enclosed drive. He has done at least one other swap for a member here successfully.

After I got the truck back, I noticed the leak. It appears to be coming from a couple of the third member studs.

When I called the guy that did the work he said they had to replace a couple of the studs, and since the housing is only made of sheet metal, they may have stripped out causing them to leak.

My question is, how do I fix this? Can I separate the third member from the housing enough to get some kind of sealant in there without removing the axles or the torque tube?


Thanks, Bob.

If it's leaking from around the stud I like Lock-tite pipe sealant w/ Teflon.

I'd drive the truck back where this crafty person did this and tell him to call you when he is complete with the task you PAID him for.

Yep- - - -he created the problem and it's up to him to fix it, assuming he has the skill to do so. He's already demonstrated a certain lack of that on the first attempt. At some point, I become reluctant to give an obviously inept person another bite at the apple, whether or not I'm paying him to try.
Jerry

Thanks for the reply guys.
BC: Should I drain all of the gear oil first and try to clean it good with brake clean? or will the Loc-tite work with the oil on the stud?

Sweet: I have read through your tutorial many times thinking I would tackle this myself.(thank you for all of the work you put in to that) None of the R&P shops in the Sacramento area wanted to work on this. I have done all of the work on this truck myself to date, but a couple years ago I had to replace the clutch laying on my back in my gravel driveway I said never again. Since this guy had already done at least one other swap I thought I would be OK. It was very expensive (quite a bit more than his original quote)

Sweet & HR: He is not willing to warrantee his work on this. He said it is over 50 years old and a poor design, so not his fault. I reminded him that there are several guys here on this forum and probably lots of others who have successfully done this swap.

He said he would be willing to take another stab at it, but at my expense. I have lost confidence in him, and this is why I just do most things myself.

At this point I am just hoping to find a solution that doesn't involve pulling the third member or axle out.

Bob.

Being 50 years old has nothing to do with it. Third members still bolt up to the banjo housing. I may have missed the whole point, but axle housings are not made out of sheet metal. I would drain the grease and remove the leaking bolts and look at the threads on the stud as well as in the housing. If the threads in the housing are indeed stripped, you have two options. Pulling the third member and installing heli-coils. But that is an invitation for oil to past the threads. I would recommend reaming the holes in the carrier housing and then drilling and tapping the holes to the next larger size. Poke around with a magnet to pick up filings and install a magnetic drain plug.

I really doubt if the threads are stripped. If the threads are good, clean things up and apply a flexible sealant. I have been using Permatex No.3 for almost 60 years and it works. Thread sealants are for tapered pipe threads. You are dealing with straight threads.

If the gasket is leaking, a quick and permanent fix is loosing the carrier from the banjo housing to where you can pry it back about 1/8". Then wrap about 3 or 4 rounds of butchers twine around the whole thing.

http://www.williams-sonoma.com/products/1164433/?catalogId=27&sku=1164433&cm_ven=Google_PLA&cm_cat=Shopping&cm_pla=default&cm_ite=default&kwid=productads-adid^45527541703-device^c-plaid^110338004503-sku^1164433-adType^PLA&gclid=CMqM58mI4M8CFQqJaQodS-8LNA

If it is the gasket, the guy probably has a point. It is difficult to get a good seal between the third member and the banjo housing with the old thin gaskets. That is why I use RTV and have been using it for 25 years or more. The same goes for OEM. However, once you have installed the unit and had oil in it, you will not be able to get it clean enough for RTV to work without removing the third member.

I have not worked much with torque tubes so I do not know what the third member is. Jeffrey

The "sheet metal" in question is .300" thick.
The metal is NOT tapped, there are studs pressed in place.
If the studs are striped or damaged, they could be replaced.

If the rear end housing bent or damaged in the surface mating area .....that might be difficult to repair.

I wouldn't waste my time taking it back to the guy that screwed up the initial installation and then offered half baked excuses to cover up his ineptitude .

If you attempt the repairs on your own..... Deve's tech article might make it easier as his technique does not require removal of the torque tube to replace the ring and pinion gears.

http://www.devestechnet.com/home/DifferentialOverhaul




.

It's time to bite the bullet and do it right- - - -You're going to have to get the rear end assembly out where it can be repaired properly eventually, so just do it- - - -don't bother with some sort of half-donkey patch job. You're dealing with the aftermath of one of those already.
Jerry

Showkey: He replaced some of the studs, and said that the new ones were not very tight. (I asked him why he kept going???)
I have not taken anything apart, but it really looks to be coming from around a couple of studs.

simplex: I have read Deves procedure, and it leaves the third member in place.

HRL: Yes, that is why I am here asking questions. Just hoping to avoid that option.

The leak is not that bad, but I wouldn't want to park it on someones nice concrete drive for very long for fear of staining it.

Yep...Jerry is correct. It's a very complicated set-up to do correctly. Look for a shop in your area that specializes in 4WD Jeeps and or Rock Crawlers those guys are always swapping differential gears. Listen to Jerry he has the real wrench experience and knowledge. It will save you bucks in the long run.

Who, Me: I checked with every R & P shop in the Sacramento area, none were interested in doing the work.
By the way the guy that did the work is in your neighborhood, about 75 miles from me.
If you know of a shop in Sacramento area, that is competent please pass on the info to me.

Bob.

Just finished this same job..........think the the rear end housing can get bent by the tight fit of the third memeber.

Wrestling or being heavy handed with the member in and out could damage the mounting surface. The threads on the member mounting studs can also be damaged by this extremely tight fit. I nicked two studs but lucky the threads could still be chased. Chasing the threads after install is also challenging as the space around the bottom mounting studs is limited. I used the split nut trick to chase the threads.

In short the member install is a PIA. The next time I might consider pulling the entire rear end....... spring shackles, bleeding brakes and E brake cables are by far easier work than wresting the 3rd member while under the truck.

You are getting good answers and answering your own question.

My take on it:
1. No one but yourself left to work on it.
2. Sounds like a whole bunch of work, possibly. "It's a very complicated set-up to do correctly."
3. Sounds like you may NOT fix it and it may still leak after awhile.
4. If it operates quietly and does not leak too much, leave it alone! wait awhile and see how much it bothers you and how nice the new ratio is.
5. If those have been known to leak, others have had to find and fix all kinds of causes.... It ain't the differential for me.
6. Switch it someday. Original is sometimes not worth saving. The more modern diffs do not have any problems like that at all!!!! and every shop in NorCal will work on them.
7. You could find out, after much work and expense, that this yay-hoo damaged something bad and he knows it. He may have tried the "Permatex/Loc Tite fixes" already. That's why he is being an axehole now. "Showkey: He replaced some of the studs, and said that the new ones were not very tight. (I asked him why he kept going???)". What if it's unfixable? Then you are dead in the driveway!
8. Buy a drip pan.
9. After being on Stovebolt for 11 years, one thing I've learned is that if I ever buy an AD I will convert to open driveshaft and associated differential in a New York minute.
10. Don't forget there is a critical break-in procedure for your diff. Follow it. Peace.
http://www.differentials.com/technical-help/ring-pinion-gear-break-procedure

Disclaimer: I do not know the exact design of this differential. If the studs were used so that the install weight was held until nut were tightened, that's OK. and if they also align the 3rd member (drop out) that's OK. However, when a person has a leaky stud, if that's what is really leaking, I don't know what that means. Is it leaking around the threads that hold the stud to the housing (banjo)? Are they leaking thru the 3rd member clearance hole at nut? Is the leak at the crack/gasket? You gotta be REAL sure of what is leaking.
Normally when you have a stud that receives a nut, the stud should have interference threads (NC-5 CSF) into the part. So that they don't turn during nut torque off. Whatever the case, would it not be easier to take out the few leaky studs, fix/chase/rethread (to any thread) the threaded holes, open up the few 3rd member flange clearance holes involved and use bolts there?
Also, since you are not messing with the gear setup Mr. Yay-hoo did, taking the 3rd member out does not seem to difficult after reading Sweets tip. But after you are sure there is no noise or other problem. Otherwise Mr. Yay-hoo will say "you took it apart, I won't be responsible".
Anyway, this would allow for repair of threads, etc. if you are so inclined as others have said. I have now said don't mess with it and mess with it. Schizo. (Which also can be called deep concentration, research and reflection regarding all options.)

Break in ????? Any body ever break in there diff on a brand new car or truck ? Think 99.999% of people just get in and drive.

When we changed the R&P from 3.90 to 3.55 and replaced all seals, bushings and bearings, we just started it up and ran it. It was/is very quiet.

We never went through any break-in procedure. Maybe my ignorance/luck has caused no problems?

Yes....a great shop one guy Tyler at Geared -UP in Grass Valley. He is a super pro and is very diligent and not full of bull a straight shooter. He did our swap and our truck was a very hard job to accomplish as the PO was a mix and mis-match type of guy. From day one until 100 miles no noise or leaks. At 500 miles I'll go back for a diff oil change. No one else wanted to even try to fix our truck but I head about him through 4-WD club he does a lot of work for them and the county.

The break in is mostly for towing on new trucks and it's in the manual not to tow before 1000 mi usually. If you want to tow or plow snow or other stress before that, it's up to you. These trucks have EDR Event Data Recording and they would check it if you brought it in for repairs. There are ways to detect loads and possibly when connector was used. Other than that we do just get in and drive.

All of the major gear MFG and sellers have this same warning I linked. Leaning towards towing but it says do the procedure and "Failure to properly break-in a new gear set can be identified by inspection, and may void the manufacturer’s warranty."

All this is up to the owner/buyer. Just wanted to inform that it is part of the "warranty". The gears will be soft annealed (lose hardness) if over heated. They must heat and cool a few times in the oil of the diff. until "broke in". (I.E. work harden under normal road load)

The gears in new trucks will be of higher quality (tolerance) than aftermarket.
My 1997 F150 has 275,000 mi. Still running on orig transmission, transfer case, differential. Chevy and Dodge will have same quality gears or better.

Can the leaks be fixed? Yes. Is it easy? Not really. Is it gonna take a bunch of special tools? No. Will it take some time? Yes.
1, Drain it. I like to pull the bottom bolt on the derby cover.
2, Get it up on some jack stands. Axle stands are fine, but might get in the way.
3, Pull the axles(yep, that is a PIA, but needs to be done)
4, Remove all of the nuts on the carrier side, and pull the Derby.
Did the studs stay put? Good. Did any spin? not so good. The studs are pressed just like the ones on a brake drum. With those neat shouldered bits that "bite into the outside of the hole. So far this is just work. If the studs are fine(not loose in the housing) Just clean(yep I said that) and inspect the gasket from the carrier to the housing. Most of the time you can push the whole torque tube forward a bit and see between the banjo and the carrier. Do not push it off the studs(darn thing is heavy)Reseal,(the Loctite stuff is very good for this kind of job) An. a d get ready to slide the whole mess back into the banjo. You can walk it back with the nuts, but go slow and do not put a lot of pressure on any one nut. Yes it is a lot like the pattern for putting a wheel back on.When it is back in contact with the Banjo, pull the nuts off 1 at a time and seal the bottom of the stud threads and around the base of the carrier. Put the nut back on and snug it in place. Repeat for each nut. Then torque it properly in stages. Reinstall the axles(yep just said that like it was easy), and reseal the derby. You might need to replace the gasket here. Add Teflon tape, or paste to the bolts on the Derby( no reason to fix the front if the back is gonna leak). Refill and drive it. The gasket on the front is tough to "make" It is a precision thing that lines up the axles in the housing. But it is not that hard to fix and seal up.
5, If the studs were loose. With the derby cover off, you might be able to reach the "heads" of the studs with a large punch. That and a big hammer will "press" the loose studs into the housing. Do not "pull" them into place.If they are seated and loose, then you will have to address the studs to Banjo fit in some other(much less fun) manner. As long as you can seal it, and get proper torque on the nuts, it should be fine. Any other thoughts would be most welcome.

Steve, great write up for him and I learned a lot. Thanks.
After re-reading Bob's post, I am still focused on his "never again" and think my 1. thru 10. is my best suggestion. Which is: wait it out. Check all the nuts and bolts on the thing for proper torque and get a drip pan.....for now. This is in keeping with trying to perceive of Bob's notion of the whole ordeal. Some things that seem like a big deal do fade in importance. 562,428 old trucks are leaking something somewhere....and plenty of newer ones are also. I am more curious as to the ratio performance and if any bad noise is present...for now. It is possible that by opening this diff up, on his gravel, is actually opening up a can of worms. I know Bob can open it up and I know I could but it could lead to your number 5 where it sort of gets sticky...real sticky.

Steve: Excellent tips! This is almost exactly what I was thinking of doing, minus pulling the axles?? I was hoping that I could pull the third member far enough back to clean and get some kind of sealant in there (permatex #3 or Loctite?) without pulling the axels. I'm not sure how far forward it will move though. I am also concerned about the studs spinning in the housing, since he said he replaced a couple. Not sure what I will do if that happens.

bartamos: You are right the leak is not that bad, and I do have other leaks. It looks like he was able to fix the leak at the oakie bushing. I love driving the truck with the new R&P and I do not hear any noise coming from the rear end.

Thanks again everyone for the great advice!

Bob.

Can't remove 3rd member without taking "C" clips/pin out and pull axles out just enough so splines are withdrawn. Not all the way out. Read repair book, Deve, Sweet tip and Steve_H.
My questions so I can learn:
1. Do studs have heads and pressed in from inside out?
2. Are they straight studs pressed in from outside in?
3. What did your guy use as replacements?
4. If the studs are loose, what do the gurus here say to do? Sealing won't tighten them but may seal them? Then are you in helical coil land or weld or one of these or equivalent:
http://www.mscdirect.com/browse/tn/...rs/Self-Sealing-Hex-Bolts?navid=12108976

I would want to know the answer to these.

This is not going to be a popular suggestion, but it will be effective. Get the complete housing out, and on a workbench. It needs to be stripped down to a bare housing, with maybe the exception of removing axle bearings, etc. Steam clean it. Inspect all the studs for looseness. If any of them are loose (particularly the ones that were replaced) Braze or silver solder the head of the stud to the housing. Use a nut and a stack of washers on the stud to assure it stays square with the housing while doing the torch work. Clean up again, using a wire brush on a drill or a die grinder to remove any flux or slag from the brazing operation. Reassemble and drive on, or keep being frustrated while attempting half-donkey partial fixes!
Jerry

Agreed. If you are going to take it apart, that's the way to fix it permanently. Welding or brazing on a casting takes a little practice. If there was a donor banjo near you, maybe that would be another option. One good thing for sure, you are going to be an expert now.
http://www.weldguru.com/braze-cast-iron.html

The axle housing isn't a casting. It's stamped steel plate with a reinforcing ring (also steel) where the studs mount.
Jerry