Transmission Drain plug Stripped: ...best practice? (1 Viewer)

Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
When I was taking the drain bolt out of the transmission pan on my 2001, it felt to tight. I got a bad feeling in my stomach. Sure enough it didn't want to go back in. I ended up filing thread at tip (starter thread) of bolt to true-out. But no luck, must of crossed threaded during last flush.

Anyone know what's best way to repair or replace with 157,000 miles on transmission & cost?

Edited 2/12/18: The threads of the transmission drain pan bolt is softer metal than that of the pan threads. In most cases one can simply buy a new OEM pan bolt & washer (gasket). Then clean the threads of the pan with a thread cleaning tool covered in grease. The grease aids in collecting metal shavings from the thread keeping them out of the bottom of the pan. Then torque to 15ft-lbf on new transmission pan bolt with new washer. If it toques to spec your good to go. ... Read on..
 
Last edited:
Joined
Oct 11, 2009
Messages
339
Location
San Diego
Either get a new pan, less than $200, or have a new hole tapped for $20. Opted for the cheaper for a buddy's LX and it been working as new for several years.
 
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
I'm leaning that way for cost saving and possibility of getting done (DIY) on a Sunday while weather nice. What did your buddy use for new plug (bolt) and gasket (washer)? I might as well do some PM while the pans off, any suggestions?
 
Joined
Oct 11, 2009
Messages
339
Location
San Diego
We just took it to a local mechanic and he matched up the new bolt and gasket and tapped it in just a few minutes. The local auto parts store had a huge selection of bolts if you wanted to DIY.
 
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
Just try a new bolt. They are softer metal than the pan, so the bolt thread should stip before the pan threads.

For a field repair that's defiantly a MacGyver solution. But since I'm in my garage and over 150K I'm going to pull pan, I might as well do PM work while pan off.

Anyone done a ~2001 A343F transmission and know what PM should be done and what parts I'll need (other than to re-tap drain plug threads or new pan)???:wrench:
Like: Gasket(s), FIPG, Oil Strainer, Magnets, Oil Pipe or Seals?
What should be Cleaned and what should be Replace?
Any helpfully tips or test to perform while pan off?
 
Joined
Nov 15, 2004
Messages
525
Location
San Diego, CA
Same thing happened to mine. I replaced the pan. Put in a new filter too. Get the Toyota gasket sealant (forgot the name, but beno or cdan will have it)
 
Joined
Mar 25, 2005
Messages
797
Location
NJ
Just try a new bolt. They are softer metal than the pan, so the bolt thread should stip before the pan threads.
+1. Same happened to me two drains ago. I put in a new plus each time, no problem.
 
Joined
Nov 15, 2004
Messages
525
Location
San Diego, CA
My plug wouldn't even come out. Would just spin in either direction. So after trying everything to get it out, just said screw it and ordered a new pan.

I would assume the PO or dealer over tightened it on mine since I was doing my first drain and fill on it. Hey on the plus side, I can at least assume a fluid change was performed before I got my hands on the truck.
 
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
+1. Same happened to me two drains ago. I put in a new plus each time, no problem.
I'll try new plug at the dealer with pan and torque wrench in-hand. If it torques to 15lb, I'll get some Toyota three bond FIPG, & three cork gaskets and a Bristle DISC https://forum.ih8mud.com/threads/fipg-removal.137162/ To remove old FIPG I used brass brush found lying around the garage, worked great with out scratching.

If doesn't hold 15lb torque I'll ask shop to repair threads, absent that I'll pick up a pan.
 
Last edited:
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
Anyone know what size the drain plug is? I need to clean out the threads in the pan, any ideas on how?
 
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
My plug wouldn't even come out. Would just spin in either direction. So after trying everything to get it out, just said screw it and ordered a new pan.
******.
I was able to get mine out by turning with vise gripes and prying with a large blade screw diver. Now I need to clean pan threads, anyone with good ideas on that?
 

hankinid

SILVER Star
Joined
Jul 27, 2009
Messages
1,619
Location
SW Idaho
Anyone know what size the drain plug is? I need to clean out the threads in the pan, any ideas on how?
Plug thread is 12 x 1.25mm. Easiest way to clean the threads would be to use a tap of the same size. Fill the recesses in the tap with grease, which should keep any metal bits on the tap. Make sure you tread the tap in straight, and go slow.


I was able to get mine out by turning with vise gripes and prying with a large blade screw diver. Now I need to clean pan threads, anyone with good ideas on that?
See above. If the threads are beyond fixing, I would simply tap oversize with a 14mm tap and use the appropriate size plug from any parts store. The "perfect" fix would, obviously, be to use a new pan...for such a simple fix, I don't think I could justify the price and time involved in installing a new pan v. an oversize plug. Obviously, ymmv.

I went a different way and installed Femco drain plugs on the engine and transmission...http://www.femco-drain.com/fcart/

Installed, the Femco plugs are about the same height as the oem plugs. Installation is one-time. Cost is about $30/each. Add another $10 or so for the coupling with hose to the drain plug.

I've installed these over the years on trucks and tractors with zero leakage. Oil changes are a breeze...oil does take longer to drain, but no oil pans to clean or other mess. I drain my LX straight into milk jugs, big tractors drain into 5 gallon pails.

The guys at the link shown ship quick and know what they're doing...good guys and technically competent. Call, ask for Ryan, tell him Steve in Idaho sent you.

No affiliation, etc.

Good luck

Steve
 
Last edited:
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
Just try a new bolt. They are softer metal than the pan, so the bolt thread should stip before the pan threads.
I misread this thinking you meant oversize bolt.

+1. Same happened to me two drains ago. I put in a new plus each time, no problem.
I see a pattern. Thanks guys for the heads up on soft bolt/plug.

Plug thread is 12 x 1.25mm. Easiest way to clean the threads would be to use a tap of the same size. ********
I went a different way and installed Femco drain plugs on the engine *****

Turn out to be a 10 x 1.50mm bolt (plug). Thanks for heads up on Femco, they look cool.

Mechanic ran the tap through, then torque in a new drain plug to 15lb. I have pan siting with a ~qt. of AT fluid in it to see if it leaks, so far looks good. Darn just realized the mechanic didn't clean thread before torqued the new plug in, I hope no metal filings were left in threads.


:hmm:I can not find new gaskets without buying a new oil strainer. Anyone know if using old gaskets will be issue?
 

hankinid

SILVER Star
Joined
Jul 27, 2009
Messages
1,619
Location
SW Idaho
Turn out to be a 10 x 1.50mm bolt (plug). Thanks for heads up on Femco, they look cool.
I'm confused. Toyota pn for a transmission drain plug gasket is 35178-30100...looking at the label I saved when I bought a washer for my '01 from my local Toyota dealer. The washer measures 12mm...not 10mm. The Femco drain plug also measures 12mm and fits the transmission perfectly.

Am I missing anything???

Steve
 
Joined
Nov 4, 2007
Messages
10,305
Location
Colorado
The washer is a 12mm and fits loosely on plug even after washer (gasket) crushed to 11.75mm from plug being torqued. If I pull the new plug back out I'll recheck, but mechanic said he used 10 x 1.50mm.
 
Last edited:
Joined
Jul 16, 2016
Messages
2
Location
LA
Just try a new bolt. They are softer metal than the pan, so the bolt thread should stip before the pan threads.

Thanks for the info.

When I took the plug off last night, it took many turns by the wrench to be able to uncrew by hand. After draining ATF, the plug would only go in a little then stuck. Somehow the plug thread was stripped. A new plug did the trick.
 
Joined
Apr 20, 2020
Messages
22
Location
uk
I am sure this has been covered before and there are a lot of cures on the net. I thought I would just say what I have done to fix the problem with my automatic gearbox drain plug (KZJ78). Quite simply (if you have any tapping experience). I drilled it out to 10.5mm and tapped with a 12x1.75 tap, This is a standard 12mm bolt thread I.E. not metric fine. I cut off a bolt to suit as a new plug. It is useful as I did this in situ, to have someone else to confirm straight drilling and tapping. Also worth noting that you make sure you are perpendicular to the mating surface of the plug. Although the sump is aluminium there does appear to be a harder metal insert which makes it stronger. I had to use a spanner to turn the tap as there was not enough room to turn a tap wrench. I used a fibre washer as I did not have a copper one and also used some PTFE tape on the thread.

Graeme
 

Users who are viewing this thread

Top Bottom