A343F transmission pan stripped drain plug repair options? (1 Viewer)

[JHZR2]

We are baselining a new 176k mile 1996 LX450. Last weekend we dropped the pan and replaced the filter. Overall looked pretty good, though there was some metallic bits on there.

Because the pan drop only gets maybe half the fluid. The intent was to drain and fill this weekend. The drain plug felt like it was going into soft material, but no issue I could see, and it torqued and sealed up fine last week.

Pull the plug, drain, and install it back with a new crush washer, torqued very gently with a good wrench. It didn’t clinch. Instead it started turning. Great. Searched on here, seems this has happened quite a few times.

In the end after trying to spin it out in different ways, I drilled it partway and then could tap it out.

I managed to drill the drain plug and not the pan.

So now what’s our best bet?

I get mixed signals on if some superceded part number for the pan is still available. Or maybe the pan for the 98-2000 LCs fits(?).

We went to the parts store and looked at options. I found some short M10x1.5 flange bolts that wouldn’t quite fit in the existing hole. So I re-tapped it for m10x1.5 and a new bolt threaded in. I torqued it to 12ft-lb which was enough to crush the washer. Cleaned it all up and put it back together with red FIPG.

If it was an aluminum pan and there was more material I’d use a time sert insert to make new threads. In this case I don’t know how much we can even really drill out of tap in that remaining material.

I don’t weld. I don’t really know who/where to go. I’d prefer to fix myself.

What has anyone else done to repair a stripped transmission drain plug thread?

I think a 7/16-14 flange bolt might be ideal over an M12 or 1/2, but are harder to find. Any thoughts/ideas/experiences?

Is any variant of this pan that fits a 1996 still available?

Thanks!

 

[Kernal]

"Is any variant of this pan that fits a 1996 still available?"

AFAIK there is no direct fit (new) pan available for the FZJ80/LX450 A343F transmission.

The photo above of the drain plug appears to show the threads of the pan have pulled off onto the plug?? Could the plug have been cross-threaded and/or overtorqued?

Either way, here's a previous discussion on the pan topic:

A343F Trans compatibility: FJZ80 & LX470

Hiya friends. I need some pro mudder opinions/advice here. I have a 97 FJZ80, where someone (before my ownership) destroyed the threads on the A343F's trans oil drain plug. They did a crappy job with an insert, and when I did a drain/fill on saturday, the insert came loose. Now, the hole is...

forum.ih8mud.com

Summary based on that thread and personal discussions with the OP (of that earlier thread):

The early 100 series pan will apparently bolt up to the later FZJ80/LX450 (A343F) but the dipstick tube is not at the correct angle or length. So the 100 series pan would require some modification to work ie: remove and transplant the dipstick tube from the 80 series pan (A343F transmission) to the early 100 series (A343F transmission) pan. Haven't done it myself however.

FWIW

 

[JHZR2]

"Is any variant of this pan that fits a 1996 still available?"

AFAIK there is no direct fit (new) pan available for the FZJ80/LX450 A343F transmission.

The photo above of the drain plug appears to show the threads of the pan have pulled off onto the plug?? Could the plug have been cross-threaded and/or overtorqued?

Either way, here's a previous discussion on the pan topic:

A343F Trans compatibility: FJZ80 & LX470

Hiya friends. I need some pro mudder opinions/advice here. I have a 97 FJZ80, where someone (before my ownership) destroyed the threads on the A343F's trans oil drain plug. They did a crappy job with an insert, and when I did a drain/fill on saturday, the insert came loose. Now, the hole is...

forum.ih8mud.com

Summary based on that thread and personal discussions with the OP (of that earlier thread):

The early 100 series pan will apparently bolt up to the later FZJ80/LX450 (A343F) but the dipstick tube is not at the correct angle or length. So the 100 series pan would require some modification to work ie: remove and transplant the dipstick tube from the 80 series pan (A343F transmission) to the early 100 series (A343F transmission) pan. Haven't done it myself however.

FWIW

The threads may be galled to the bolt and ripped out. They never saw 16ft-lb when tightening when they failed fwiw.

I’ll check that thread. Thanks. I had seen a few with failed pans but no good resolution.

 

[WCBlueSky]

Could get a used pan in good condition from classifieds or maybe @slow95z.

 

[Pascoscout]

If the threads in the pan look solid and it holds torque I can't see anything wrong with your repair. If you needed to go larger to get better cut threads I'd go to a m12 bolt. Looks to be plenty to material left in that thickened area to go a little larger. I personally would not add a SAE bolt to the mix.

 

[slow95z]

Could get a used pan in good condition from classifieds or maybe @slow95z.

i do still have a few of them if he wants to go that route.

 

[Congo Cruiser]

i do still have a few of them if he wants to go that route.

In the same boat. Any options for getting a drain pan with hood threads from someone?

 

[calokie]

what's the thread size for the stock drain plug? Can heli coil insert be used?

 

[Congo Cruiser]

what's the thread size for the stock drain plug? Can heli coil insert be used?

I’ll have to look that up.

I’m thinking I’ll have to drop the pan and have those threads repaired. Drill it I guess. I’m not so experienced, so don’t know if a heli coil would work - perhaps best to repair it proper with the pan off the vehicle.

The pan is NLA.

Thanks for the reply though. I have a few friends I may call in to help.

 

[BILT4ME]

I’ll have to look that up.

I’m thinking I’ll have to drop the pan and have those threads repaired. Drill it I guess. I’m not so experienced, so don’t know if a heli coil would work - perhaps best to repair it proper with the pan off the vehicle.

The pan is NLA.

Thanks for the reply though. I have a few friends I may call in to help.

Again, @slow95z may have a pan available.

He's in GA, so at least on the right side of the country for you.

If he's available, he'll chime in here.

 

[slow95z]

I do have some but they are on good transmissions and I don't want to pull them plus time is crazy limited right now. He and I are talking on options to fix it locally

 

[calokie]

Machine shop, weld and re tap to correct size

 

[Congo Cruiser]

Again, @slow95z may have a pan available.

He's in GA, so at least on the right side of the country for you.

If he's available, he'll chime in here.

Have always enjoyed your posts…thanks for replying.

Yes, @slow95z and I have been in touch. None available right now, but he gave me some great tips.

Will get started shortly.

Thanks again.

 

[sonocruiser]

Hoping to get some insight into what a PO might have done to remedy (what I assume to be) a stripped drain pan bolt. I went to drain and replace the ATF last weekend only to discover a very... interesting... looking transmission drain pan bolt situation at step 1:

As far as I can tell, its not leaking much, if any ATF--no spots on the driveway anyway.

Anyway, taking a closer look, it doesn't look like there's any gasket maker on the interface between whatever is inserted within the pan and the bolt:

Thought I'd get a second opinion before opening up what might be a can of worms with a NLA part and maybe inspire some others. I note that there was also this nice strong magnet stuck on the bolt, which makes me think PO was taking this the bolt on and off to drain and refill. He took really meticulous care of pretty much all of the fluids, just came up with some very interesting solutions to things.