HELP! transmission case repair?

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Ok maybe lazy was a bad choice of words. I'm not politically correct and I try not to sugar coat stuff, because I don't wanna give anyone false hope. Maybe it comes out a little harsh at times. My bad.

But, IN MY OPINION, there's not enough "hole" left before the flare angle in the transmission for enough threads to drill and tap. You MIGHT have room enough for two full threads. Not only that, but what of any "other" cracks? When you go to drill and more transmission case breaks off, there you are.

Another case has a 100%, that's ONE HUNDRED PERCENT chance of fixing your problem.

Sorry, I wasn't trying to cause a war with our coveted transmission expert, so I will bow out. Yall can have it.
 
CudaFactHackJob said:
Oh no, am I involved in a controversy?!? JB Weld has it's place, and I've used it for many many repairs and modifications. I actually have used it to repair inlet castings on TF transmissions!Lots of friendly advice on here on how NOT to fix this problem..."replace the case"...."do it right"..."any competent welder"...you guys are DREAMERS...not dealing with the reality of the situation. For me, this is a twenty minute fix. For some of you guys, it's a days long job involving over a thousand dollars...but you wanna "do it right"...Oh, and this is not "an open passage into the transmission"...if it was, there would be no need to avoid contamination.
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I'd have already welded it up. The more I look at it, the more I think the best way to solve this is to cut it off flush and then weld a boss or an AN fitting to it. The hole can be plugged when cutting it off flush so no chips get in and that isn't a problem when welding the new piece on. Cutting threads is the most likely operation to dump chips in the case, and you can skip that with a new boss or fitting.

JB weld may have its place, but this ain't it. I may be a dreamer, but you're obviously not a welder.
 
72bluNblu said:
I'd have already welded it up. The more I look at it, the more I think the best way to solve this is to cut it off flush and then weld a boss or an AN fitting to it. The hole can be plugged when cutting it off flush so no chips get in and that isn't a problem when welding the new piece on. Cutting threads is the most likely operation to dump chips in the case, and you can skip that with a new boss or fitting.

JB weld may have its place, but this ain't it. I may be a dreamer, but you're obviously not a welder.
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Yes, I would go along with that, IF the OP can TIG really well, or maybe know someone who can. That's a repair I'd actually endorse.
 
Not a welder? Moi?? I removed the head from a 250 ford inline six and saw that it had been recently rebuilt, but nothing had been done to raise the compression. .030 deep dish pistons. I ran two up to the top, loaded my trusty Northern Tools mig with aluminum wire, hooked up my argon, cranked up the wire speed to the max, and WELDED domes onto the pistons. No, SIR, I did NOT remove the pistons. I also did a Opel 1.9 the same way. They both ran like striped-azzed apes. But I would NOT recommend welding up this case. Cut it off flush and drill and tap. If the tap gets sloppy, use JB weld as a "sealer"...
 
Can you get a better picture of the case threads left in the case, that fitting is designed to be a wedge fit and if over torqued will break out like that.
Transtar sells a case repair fitting just for this issue it is a special fitting that bottoms out in the drilled case area and repairs the case, provided there are enough threads left to hold it. It is a straight line long threaded fitting with a flat seat on the end.
This is a common issue.
(Re rear case line repair fitting)
Lon
 
Well, thanks for all the advice (really!)... I can do without the vitriol. Why can't folks make their pitch for a solution, or even say why they think someone's solution won't work without questioning somebody's sanity or competency?

CFD244 said:
OP....Have you asked a transmission shop? I'm sure that they have seen this before. I too would be leery heading out for a long road trip with "will it hold" in the back of my mind. Stress you don't need.
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Thanks CFD244! Here is the crux of the problem for me. I'm building this car for long distance road trips (read: several thousand miles for one trip), that's why I'm going through the trouble of installing a 4 speed automatic in a car that never had one (1970 Dart). I don't need a fix that might work when I'm crossing Southwest deserts in August! If this were simply a car to drive locally and occasionally, some of these suggestions would be worth a try.

I'm taking the trans back to the performance trans shop that built it for me and they will try to effect a permanent fix on the existing case (I like the idea of grinding it flat and then welding a new aluminum bung, or maybe an aluminum bung with a steel insert - do they make such a thing?). If they can't effect a repair they gave me a cheap price to swap all the internals to another case since they just rebuilt it (0 miles). I have a wanted ad here looking for another case, but no bites yet. The shop is looking for one, too. Fortunately all the case modifications to make this fit are in the 4th speed extension housing so I won't have to do that again.

Again - Thanks to everyone for their insights, I really appreciate you taking the time to respond. I'll let you know how it turns out.
 
str12-340 said:
Well, thanks for all the advice (really!)... I can do without the vitriol. Why can't folks make their pitch for a solution, or even say why they think someone's solution won't work without questioning somebody's sanity or competency?



Thanks CFD244! Here is the crux of the problem for me. I'm building this car for long distance road trips (read: several thousand miles for one trip), that's why I'm going through the trouble of installing a 4 speed automatic in a car that never had one (1970 Dart). I don't need a fix that might work when I'm crossing Southwest deserts in August! If this were simply a car to drive locally and occasionally, some of these suggestions would be worth a try.

I'm taking the trans back to the performance trans shop that built it for me and they will try to effect a permanent fix on the existing case (I like the idea of grinding it flat and then welding a new aluminum bung, or maybe an aluminum bung with a steel insert - do they make such a thing?). If they can't effect a repair they gave me a cheap price to swap all the internals to another case since they just rebuilt it (0 miles). I have a wanted ad here looking for another case, but no bites yet. The shop is looking for one, too. Fortunately all the case modifications to make this fit are in the 4th speed extension housing so I won't have to do that again.

Again - Thanks to everyone for their insights, I really appreciate you taking the time to respond. I'll let you know how it turns out.
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Well good luck with it! Sorry it happened in the first place.
 
I'd take it to a weld shop. It's not structural so perfection is overkill. If it gets some porosity in it but welds up ok, they make sealers. It's pipe thread anyway, so use the teflon sealant goop if it's got a wee pore or two. You're going to re-drill and re-tap it after it's welded anyway, unless that welder gets the Van Gogh'd bit lined up PERFECT, so it's not like it's going to be exact.

If that fails, do you have enough meat to go up a size on the NPT, and then use a NPT bushing with the new size on the outside and the old size on the inside? McMaster has a ton of those.

I'd really try not to go deeper with the threads, though. Remember, it is NPT, so the deeper you cut, the wider you cut, and the pilot hole is only sized for the correct depth of thread.

I would NOT jam steel wool in there. That's asking for steel fibers to come loose in the hole. I might make a steel dowel or something to plug the hole, or a plastic one, or....? But nothing made of loose steel shavings!
 
This is an amazing thread. I've never seen so many negative opinions based entirely on opinion; not fact, and not experience. What all threads have in common is the question of procedure about something the op is unfamiliar with. Usually, commenters have some experience with the problem or solution and give advice based on their experience. But in this thread we have a multitude of nervous posters commenting out of fear and encouraging the op to do exactly what he's trying to avoid; replace the case. You guys are AMAZING!! I'll stay tuned for further entertainment!
 
CudaFactHackJob said:
Not a welder? Moi?? I removed the head from a 250 ford inline six and saw that it had been recently rebuilt, but nothing had been done to raise the compression. .030 deep dish pistons. I ran two up to the top, loaded my trusty Northern Tools mig with aluminum wire, hooked up my argon, cranked up the wire speed to the max, and WELDED domes onto the pistons. No, SIR, I did NOT remove the pistons. I also did a Opel 1.9 the same way. They both ran like striped-azzed apes. But I would NOT recommend welding up this case. Cut it off flush and drill and tap. If the tap gets sloppy, use JB weld as a "sealer"...
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So how much out of balance were these motors with all the gobs of weld u added. I bet not 2 pistons weights the same after the welding. Actually I find this kinda far fetched. Kim
 
I measured 1/2" down from the top and cc'd each cylinder to make sure that they were balanced. I'm sure I have a pic around here some place...but it sounds like you wouldn't believe that it ran like a scalded dog anyway. Without vibration....I did it twice and I'll do it again, but that doesn't mean I recommend it....don't attempt anything like that yourself..
 
Sonnax makes a repair but you still have to deal with machining and debris.
22000-01K.jpg
 
str12-340 said:
Today I went to to install the fittings for the transmission lines in my freshly rebuilt A500 (RH42). As I tightened up the fitting the part of the case that is threaded for the fitting broke apart. Is there anything that can be done to repair this or do I just have to find a whole new case and have the internals swapped?

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A good welder could "V" the required weld area and weld it back together. The weld would be into the threads requiring it to be tapped out. Al does weld well, but that said I would be more inclined to swap the internals into a good case. The time required is minimal, like an hour. Then the cost of a good used housing. Seals and most gaskets should be reusable as it has not run. The issue with welding your case is, what if it let's go again driving down the road. If that happens you need another case and likely total rebuild on that one.
 
str12-340 said:
Today I went to to install the fittings for the transmission lines in my freshly rebuilt A500 (RH42). As I tightened up the fitting the part of the case that is threaded for the fitting broke apart. Is there anything that can be done to repair this or do I just have to find a whole new case and have the internals swapped?

View attachment 1715926210 View attachment 1715926211
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I would try JB weld metal epoxy & teflon tape on the fitting it might be worth a shot
 
I'll tell you what I have done in that exact case on a Chevy transmission though. V out the edges of the case and the broken part and clean the paint off and clean trans and part with brake or carb cleaner really well. Screw a steel 1/8" NPT fitting into the hole but not tight, place the broken part in place on the threads, weld it up and you won't even have to rethread. The melting point of aluminum is so much lower than the steel that it will fill in the threads at the vee and leave the steel fitting intact. Once welded to satisfaction, remove the fitting and you're good as new and ready to screw in the original fitting.
 
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