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Today I tried to install transmission mounts. As you can see I messed up. Not sure how I did it so easily. I was holding the socket wrench with the socket between my middle fingers. As soon as it got snug, that happened.
Am i completely screwed, or can someone give me some advice on how to proceed.
Is that the bolt to the trans or the one to the trans mount. For the trans you can try to retap the hole with bottom tap. There probably is enough good threads to work, if not a heli-coil. If its the mount you can do the same of buy a new one.
What kind of trans? In many cases, the trans mount bolt hole is a through hole. You can just put a nut on the top. This photo is a TH400 tailhousing, for example. FYI, it is also extremely easy to swap the tailhousing (assuming we're talking about a trans with a bolt-on tailhousing).
What kind of trans? In many cases, the trans mount bolt hole is a through hole. You can just put a nut on the top. This photo is a TH400 tailhousing, for example. FYI, it is also extremely easy to swap the tailhousing (assuming we're talking about a trans with a bolt-on tailhousing).
This is what it looks like, not sure if it goes all the way, i will have to crawl under to make sure.
The bolt looks a lot newer than the washer. It makes me wonder if the wrong (to short) length bolt was used and pulled the threads out. Only 3 threads were pulled, which leads me to my assumption.
A rule of thumb is that a bolt should have at least the same depth of engagement as the bolt diameter (3/8" bolt, 3/8" thread depth, etc.). Do .some measuring and checking for good threads.
The easiest solution depends on if the hole is through hole...longer bolt and nut. Heli-coil would work also, but might be harder if working on your back under the car.
........Just my two cents worth
Let us know your progress. I think you will likely be ok by running a tap through the hole as suggested.........just be careful starting it. A longer bolt that sticks out the top side and a nut might be something to have on hand. Get a bolt to go in the hole deeper should be your plan.
Taps, just a note. Taps come in three different chamfers or (leads). Taper, plug and bottoming. Bottoming being the shortest usually 2 to 3 threads. Plug being mid range 3 to 5 threads and the longest being taper which is the best to used for mostly repairs where their is room at the bottom of the hole or a thru hole. If this is truly a thru hole application your best chance would be to acquire a tap with a taper chamfer. Best shot is installing a Heli-Coil inert which will give you the most strength.
Thanks
Wayne
I think people are waaaay overreacting to this. First, it appears that not all the threads in the tailhousing were stripped out. Before doing anything, see if a longer bolt will tighten up in the remaining threads. You may want to run a tap through the hole first to clean it up. Be VERY careful to avoid doing more damage. Second, while your trans photo was pretty much unhelpful, and you still haven't told us WHICH transmission it is, from the modulator location in the photo it APPEARS to be a TH350. The bad news is that those mounting bosses are part of the case, not the tailhousing. The good news is that there is probably enough room above the boss to get a nut on the bolt. Temporarily remove the vacuum modulator to make that easier. Third, if you do choose to install a helicoil, this is not that critical. You don't need a guide block. If the bolt isn't exactly perpendicular to the boss, it won't be the end of the world.
Got it working, thank you everyone for the advice. I was able to clean up the remaining threads and get it done. Thank you everyone for the help. Now on to fuel tank and rear end.
Clean out the hole of dirt and grease. Use Red Loctite on your new bolt after determining the proper length and you will not have to tighten the bolt as tight. Let dry over a few days. I have used a metric bolt as the metric tap will cut new threads and does work. Again using Red Loctite.
On a restoration I use a new/used trail-shaft, chase the threads and clean out the bolt hole. Pick an in good condition factory bolt, run a die down the bolt threads and use mineral spirts to clean.
Last edited by davebw31; August 26th, 2018 at 09:14 PM.
August 25th, 2018, 09:56 AM
