AT pan was leaking following switching to syn. Took it to the transmission shop and they noticed the different bolts and washers all over snd determined the previous shop stripped the screws when the transmission was rebuilt. The transmission case is aluminum and the bolts are iron I think, or steel. I am bringing it in on Monday to be fixed. He will be using Toyota's "make a gasket" on the pan instead of a cork or rubber gasket. My question is...can you even re-tap aluminum and how well can this be repaired. WHAT A PAIN IN THE A$$!!
Leaking Tranny Pan 97 Avalon Stripped Pan Bolts
- Thread starter parimento1
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Not useful to go back to the original butchers? Idiots!
Yes aluminum can have helical inserts installed. One famous brand is Helicoil.
Yes aluminum can have helical inserts installed. One famous brand is Helicoil.
Yes I was gonna take off the pan myself and just install a new gasket until he pointed out that they were indeed stripped! thats good that it can be tapped though, because having a new case put it, will be more than the car is worth...even the transmission rebuild was about as much as the car is worth. The transmission is out of warranty by about 6K miles, I wish I noticed this sooner. I took it back to the original butcher 3 times due to slow engagement of gears in the mornings, which was found to be because of debris in the valve body, and also a loose differential bearing that magically fixed itself ( i think it popped into place). Overall they did a pretty good rebuild it shifts like magic and shifts quicker and more positive than it did even when it was new in 97. But stripping the screw hole is aggravating!
Have them install heli-coil inserts.
I will ask, from your experience, do most shops have/know how to use helicoils?
I would hope so.... They are pretty hard to screw up in aluminum. Just make sure when you drill the hole that you are going in straight.
You can buy a kit with the drill bit, tap, heli-coil inserts and install tool for about $20 range. You might have to buy extra inserts.
Being it is aluminum that will make the job pretty easy.
You can buy a kit with the drill bit, tap, heli-coil inserts and install tool for about $20 range. You might have to buy extra inserts.
Being it is aluminum that will make the job pretty easy.
good, the shop I am taking it to is a transmission shop, and he pointed out the stripped holes, so I would [censored] since he pointed that out that he knows how to fix it. I will find out on monday and let you guys know. Thanks for your help.
Originally Posted By: parimento1
I will ask, from your experience, do most shops have/know how to use helicoils?
I doubt it very much, but if you bring it to Clovis, I can install them because I know how. Seriously though, an automotive machine shop with a lift is what you'll more than likely need to seek out.
I will ask, from your experience, do most shops have/know how to use helicoils?
I doubt it very much, but if you bring it to Clovis, I can install them because I know how. Seriously though, an automotive machine shop with a lift is what you'll more than likely need to seek out.
JTK
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If the shop isn't familiar with Helicoil installation, they will be after this job!! I couldn't imagine having to do ~16-20 tiny ones like that.
Joel
Joel
I think only 5 or 6 of them are stipped, so it could be worse haha. I wonder what the charge will be for this...I dont think I want to know.
JTK: are you a mechanic in the Buffalo area?
JTK
$100 Site Donor 2025
Originally Posted By: parimento1
JTK: are you a mechanic in the Buffalo area?
Nah, just a pretend one.
I'm only equipped to do lighter stuff for family and friends, that's about it.
Joel
JTK: are you a mechanic in the Buffalo area?
Nah, just a pretend one.
Joel
Helicoils or tap them for slightly larger bolts. Even if you have to mix SAE and metric.
Depending if the gasket will allow this [it should], you can use a slightly larger bolt diameter.
It is an option that is easier and cheaper.
Depending if the gasket will allow this [it should], you can use a slightly larger bolt diameter.
It is an option that is easier and cheaper.
good idea, I will tell the mechanic about this tomorrow. Do you need special taps for aluminum. I also hope there is enough room to tap a bigger screw. Also, there is no gasket hes gonna use some Toyota silicone gasket maker for it, so I dont need to worry about that, it will take the shape of whatever he puts in there
I actually did this the 1st time I dropped the pan on a previous car a few years back.
I only stripped 1 or 2 bolts though, but it still leaked. It cost ~200 bucks to fix. I can't remember if they used helicoils or simply tapped it to larger bolt/holes.
I never realized how soft aluminum was until that moment.
I only stripped 1 or 2 bolts though, but it still leaked. It cost ~200 bucks to fix. I can't remember if they used helicoils or simply tapped it to larger bolt/holes.
I never realized how soft aluminum was until that moment.
Standard taps work great. And the chips fall down - real easy to do.
Search for a slightly larger bolt that will fit, first.
Search for a slightly larger bolt that will fit, first.
Took it in today to the mech he used longer or larger bolts not sure which one, plus a silicone gasket, he said it should not leak, but to bring in back in a week and he'd check it
It is easy to retap aluminum but to what end? Far better off to enlarge the hole and instal heli-coil. This way you will have steel insert for the steel bolts to enguage. Some knuckle head probably had the butterfly impact gun dialed up too high. I mean you do not use that much force to tighten pan bolts. In fact I use a torgue wrench but even a t-handle is more then enough or a thumb rachet etc.... Lets hope they did a beter job on the inside of the transmission then on the outside!!
yea I think the internals are ok lol as when he dropped the pan today to change the gasket it was nice and clean. I just hope he fixed the leak! Another thing I dont understand is why does Toyota use steel/iron screws in an aluminum case! It is like asking for it to strip, I will never understand that!
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