I have a 98 Jeep Cherokee 4x4 with AW4 transmission. I recently changed the transmission fluid and the previous owner must have stripped several bolts on the pan and used excessive rtv to cover it. What is the best way to replace the bolts and is it better to just go a little larger on the bolt?

 

Drilling and tapping one size up is just about the only solution.

 

How many bolts are we talking about? I recently had my pan down and when I went to put it back up, one of the bolts stripped when torquing it. Since it was just 1 bolt, I filled the hole with RTV and stuck the bolt in and tightened it as best I could. Check for leaks everyday for several days. All is well.
If its SEVERAL bolts, now you're talking about issues with the whole pan being able to be kept up there tight enough so nothing leaks. I'd agree that your only option at this point would be to tap it and go one size larger. It may be a pain in the rear, but you might as well do them all so you have the same size bolts all the way around. Unless you wont mind playing the matching game with different size bolts.
Are you sure its the threads in the trans that are bad and not the bolt thats stripped? I'm guessing its the trans because that is made of a softer material than the bolts....

 

E-Z Lock threaded inserts because I am OCD and want all the bolts to be the same size. You will still have to drill and tap, but then put an insert in. Kind of like a helicoil, but much better for this type of application.

 

I have the same problem with my trans pan. I'm going to install helicoils. From what I've read, it's the right way to fix it. I have all the stuff, just haven't gotten around to doing it yet.

 

How big do u have to drill to fit a helicoil for the proper size bolt?

 

I was thinking about heli-coils as well, but figure a tap would work just as well to fix the threads. If you want really good threads, then do the heli-coil or EZ-locks.... Or even nut-serts, but those take a hammer i believe.... and probably reaming out your holes (hahahaha) to get rid of the threads so the nut-serts will go in. or leave threads, just have the correct size nut-serts.... I CAN tell you that if the threads are messed up real good, you WILL have to tap them to a bigger size. You can run a tap in there and fix the threads to be the same size. You will have to go bigger. Just find out the threads courseness and pitch then go 1 size thicker....

I'm certainly not the know-it-all guy for this application..... I've only had to use a tap and die set 2 times ever. and never had to use heli-coil or other things of that nature..... knock on wood!

 

The kit you get will tell you. For the AW4 trans pan bolts, which are M6x1, I believe it's 1/4". Drill it, tap it, insert helicoil, and use the original (or same size as original) bolt.

Good info from another site: https://naxja.org/forum/showthread.php?t=1145801

 

Did you fix yours? I had one stripped hole and two holes that were bigger than the rest (PO probably stripped them and tapped next size bigger). I was able to drill all three out to 1/4", tap, and insert helicoil. When reinstalling my pan, another hole stripped. I was able to drill and tap with the pan on. I don't have any leaks, but my Jeep is ripped apart and undrivable at the moment so I don't know if it's truly leak free yet.

Good luck with yours.

 

I've tapped to the next larger size and didn't worry with a helicoil. As I recall the originals are M6, and I tapped to a 1/4-20 tap without needing to drill. Just have to keep track of which screws are different next time, and remember that aluminum thread strip real easy..

 

They strip real easy. More than one way to skin a cat, I'm glad you got it fixed.