Hot Rod Forum banner

T- 375/400 - how high should fluid be in pan?

2K views 4 replies 3 participants last post by  ggevaert 
#1 ·
Hi,

I have a THM 375 that came with no dipstick (same as THM 400 except for internals). I have been trying to figure out what the proper level of fluid in the pan should be so I can mark my after market dipstick.

I have been told that it is Pan rail level and I have read on some sites that it is 1/4" below pan rail height. I got the pan rail level from 2 members on this site so I would normally go with that but the 1/4" below pan rail just happens to match up perfectly with the full mark on my after market so that gave me pause to double check. :confused:

To even further complicate things I called the local transmission shop that rebuilt my tranny 2 years ago and that guy said it should be right below the opening where the dipstick goes in, which is 1/4" ABOVE pan rail. So that left me even more confused as I tend to trust that guy - he did rebuild my tranny. (maybe he misunderstood the question?).

I also bought a book about thm 400 trannies and, of course, it does not talk about that at all, only to ensure it is where the dipstick says it should be.

So, help! Anyone?

If no-one knows for sure then could i have somone measure their THM 375 (or 400) dipstick from the bottom tip to the top where the middle metal meets the cap (on the inside) and I will compare it to mine. I already have all the measurements for my pan, dipstick tube so I will know how to mark it then.

Thanks
Gary :welcome:
 
See less See more
#3 ·
Fluid height

Thanks Cobalt327 and Art,

Just found another discussion on the Chevelle site having it even higher, that's another 1/4" higher yet:
* The full mark on the dipstick should be level with the top of the hole where the dipstick goes into the trans.
 
#5 ·
Got it

Thank You Crosley, I was just frustrated with trying to get that answer.

so I have my fluid 2 pints short then - will fill up and go with that.

Also found this:

http://www.jakesperformance.com/Transmission_FAQ_Page.html

How do I know that the dipstick is reading correctly?

The fluid level should be even with the pan gasket when warm, idling in park or neutral. You can confirm this level on a dipstick before install, or once it is installed, you can loosen the pan slightly to let excess fluid drain, tighten the pan back up, clean the dipstick, re-insert and check, and then mark the indicator at the proper level.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top