changing trans pan gasket

[ugabulldog]

When changing atf fluid, I messed up and had the wrong torque written down for the drain plug and messed up the pan threads. So I am replacing pan and gasket with new ones. This is on an 07 Tundra 50k miles. I now know drain plug bolt is 15 ft lbs. The gasket is heavy duty, see picture. I have never done this before, have read I need to torque bolts in criss cross pattern. The only torque specs for pan bolts I found online (not from Toyota directly so not sure if it is correct) is 8 ft lbs. I was going to use my torque wrench to loosen current bolts by starting out low and increase torque until they loosened to find out current torque. I will clean magnets and put on new pan. Is there anything else I should know or be aware of when changing gasket, obviously make sure everything is clean, maybe clean trans metal mounting surface with brake cleaner? I am debating on whether or not to change strainer also since I am already this far (I would use torque wrench same way to find current torque)....thanks

 

[Astro14]

The break-away torque will be far higher than the tightening torque, so I don't think your method is accurate.

The 15 lbft is extremely high for a transmission pan. 8 even seems too high... 6 would be my guess. Even, modest torque is the way to get them to seal.

Might be time to join the Tundra forums. They often post detailed information.

For example:

https://www.tundratalk.net/forums/tundra-general-discussion/142505-need-torque-specs.html

This guy says 65 inlb - which is a lot closer to what I've seen on pan bolts...

Flushing the fluid on your truck isn't hard - but to do it, you have to pin the transmission cooler thermostat open, or you won't get any flow. Setting the level is easy, but it requires knowing the fluid temperature, which requires Toyota's Techstream, or a good IR gun.

 

[Chris142]

Don't use a tq wrench to loosen. It ruins the calibration

 

[JeffKeryk]

Just buzz of the bolts. Clean all mating surfaces as best as you can.
Since you have a new pan, the pan mating surface should be flat.
Use a 1/4 ratchet to evenly snug up pan/gasket. I would consider an inch foot torque wrench. The cheapo HF model will be fine.

As I recall, the torque is something like 65 inch pounds, which is 65/12 or 5.5 foot pounds.
I'm sure I over did the bolts on our 2001 Tundra... It does not leak.

 

[ugabulldog]

Thanks for all the replies,..... I was wrong on the pan torque I found. 8 was the NM, so it converts to 6 ft lbs. I am a member of tundra forum and posted strainer bolt torque question there. Should I go ahead and replace strainer also? I do have the Toyota tsb so I can check fluid level at right temp.

 

[demarpaint]

I agree with Astro14. I used 70 inch pounds [very close to 6 foot lbs] for my Jeep's Nag1 transmission pan. The gasket is a similar material, and supposed to be reusable. I went with new. Everything went together nicely with a cross pattern, and taking the nuts down in three increments.

As long as you know the proper procedure and feel comfortable doing it I'd change the strainer if that is a required maintenance item.

 

[CT8]

inch pounds.

 

[Rhymingmechanic]

Change the filter while you're in there. I can't tell from the photo if it has bolt holes, but there will be a torque spec if it installs that way.

Your pan gasket seems to have metal inserts at the holes to prevent overtightening, so you can be confident in getting that right with a torque wrench. With plain fiber gaskets and a 3/8" drive torque wrench, I've gotten the sense that I could tighten the bolts indefinitely and the wrench would turn and then click each time. I finally got a HF 1/4" drive torque wrench for my next pan drop. I also recommend snugging everything with a small 1/4" ratchet first.

 

[ugabulldog]

I found the torque specs, strainer bolts 7 ft lbs, pan is 65 inch lbf. I have a 3/8" torque wrench with ft lb,... will I be ok converting ft lbs to inch lbf, or should I get a 1/4" torque wrench with inch lbf?

 

[dawgn86]

is this an OEM Toyota gasket?

 

[ugabulldog]

...

 

[nthach]

I would do the filter at least once during ownership in any Toyota/Lexus/Scion with a 5-speed or greater tranny.

Don't forget the O-ring if it has one. That filter looks like the one for the Lexus LS430.

If your torque wrench starts at 5ft-lbs, you'll be fine with the conversion.

 

[ugabulldog]

Ok, thanks, yeas O-ring also. I am going to use OEM gasket and strainer. Would rather pay a little more and be sure about quality.

 

[doitmyself]

Originally Posted By: ugabulldog
I found the torque specs, strainer bolts 7 ft lbs, pan is 65 inch lbf. I have a 3/8" torque wrench with ft lb,... will I be ok converting ft lbs to inch lbf, or should I get a 1/4" torque wrench with inch lbf?


Very few 3/8 inch torque wrenches go down below 10 ft. lbs.. And remember, nearly all of them are NOT calibrated to be accurate below 20% of the highest reading. I.e., an 80 ft. lb. wrench is only calibrated good down to 16 ft. lb., even if the scale goes lower.

 

[ccs368]

Originally Posted By: ugabulldog
I found the torque specs, strainer bolts 7 ft lbs, pan is 65 inch lbf. I have a 3/8" torque wrench with ft lb,... will I be ok converting ft lbs to inch lbf, or should I get a 1/4" torque wrench with inch lbf?



I used a craftsman 3/8" microtork with a 25-250 in-lb scale. For my pan screws, I don't fully recall but it was something like 48 in-lb for the transmission pan screws. All I cared about was running the screws consistently in a criss cross pattern knowing I used a similar gasket material and thickness as the OEM, no rtv, and no mangled pan from abusive prying. No issues what so ever and I torqued them 3x per bolt. Because my specification has a relatively low torque requirement, I tend to go slower because once you feel the "click", sometimes you go a bit further if you rush. So for me I was happy with this tool and outcome of the service. This will cover your strainer too.

It should also cover the range of the drain bolt (15ft-lb or 180 in-lb) with this exact same tool unless you are one of the DIY's that have a good feeling about tightening drain bolts. Not sure why but for oil drain plugs, I never use a torque wrench but for the tranny drain bolt...I did. Can never be too careful.

 

[RyanY]

Originally Posted By: ugabulldog
I found the torque specs, strainer bolts 7 ft lbs, pan is 65 inch lbf. I have a 3/8" torque wrench with ft lb,... will I be ok converting ft lbs to inch lbf, or should I get a 1/4" torque wrench with inch lbf?



Yes...get the correct tool for the job and you can be confident in your repairs.

Just a note of caution. I have a Harbor Freight 1/4 torque wrench. Very accurate but the click is not very loud...have to go more by feel than sound. It would be a good idea to practice first to get the "feel" of the tool before you use it.

 

[ugabulldog]

Thanks for all the help, I feel confident on changing the gasket and strainer, however...… I tried the overflow drain bolt VERY GENTLY on the drain hole and got a turn in by hand, more than I could get with drain bolt, so I am thinking it is the drain bolt threads that are damaged more so than the pan threads. I have read the bolt is softer than the pan and hope this is the case..... I can see the pan threads look a little buggered but don't look too bad. I am getting a new drain bolt from dealer this week. I am planning trying tne new drain bolt, or maybe first buying the same size bolt and thread size in a grade 8 bolt and cut a couple of notches in it to make my own thread chaser bolt (NOT tap to make new threads) put some atf fluid on it to catch any metal shavings if there are any thread into drain hole and see if I can clean up pan threads, see if I can get 15 ft/lb torque on new drain bolt doing this way. Thoughts on this?

 

[ccs368]

Originally Posted By: ugabulldog
Thanks for all the help, I feel confident on changing the gasket and strainer, however...… I tried the overflow drain bolt VERY GENTLY on the drain hole and got a turn in by hand, more than I could get with drain bolt, so I am thinking it is the drain bolt threads that are damaged more so than the pan threads. I have read the bolt is softer than the pan and hope this is the case..... I can see the pan threads look a little buggered but don't look too bad. I am getting a new drain bolt from dealer this week. I am planning trying tne new drain bolt, or maybe first buying the same size bolt and thread size in a grade 8 bolt and cut a couple of notches in it to make my own thread chaser bolt (NOT tap to make new threads) put some atf fluid on it to catch any metal shavings if there are any thread into drain hole and see if I can clean up pan threads, see if I can get 15 ft/lb torque on new drain bolt doing this way. Thoughts on this?


Ok, so what I've read is you switched the overflow bolt (known good male threads) and installed into the drain hole (suspected damaged female threads) and only got one revolution before it binds up? This is what I would do. I would drop the pan which you were going to do anyways since you were replacing the strainer.

Then you can visually inspect carefully what you're up against. If the drain hole threads are buggered up, it is likely (or hopefully) the first several threads and not destroyed throughout the entire bore.

Now I would carefully try your modified bolt but engage the suspect drain hole from the inside of the pan and not start repair from the normal outside direction. Why? Because the backside of the threaded hole is likely good and your modified bolt will engage and start perfectly square from the backside. You want to be perfectly square and chasing from the other side gives you a better chance of success imho. As you tighten/back off/repeat, all the buggers should now be ejecting itself out the front side of the suspect drain hole.

The biggest assumption is the drain hole in the pan is threaded all the way thru and not a partial thread which would not make sense at all but stranger things has happened.

Good luck.

 

[ugabulldog]

thanks for the suggestion ccs, it looks like it is threaded thru, there are only about 3 threads though. However, I was hoping not to drop pan with my solution.

 

[RyanY]

Originally Posted By: ugabulldog
thanks for the suggestion ccs, it looks like it is threaded thru, there are only about 3 threads though. However, I was hoping not to drop pan with my solution.


Aren't you planning to drop the pan anyway, to change the gasket and filter? Or did you already do this? I would feel safer removing the pan before jacking around with threads, but that's just me.