Thread: Turbo 400 Speed Housing Not Standard

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I have what I think is a turbo 400. I ordered a new speedometer housing for my turbo 400 and get it here and it doens't fit. My housing diameter is smaller. Could I have a pre 65 400? Looking for a speed gear housing to fit this thing, someone tore the old one up.

pictures may help

what the shape of pan

Not sure if pictures will help but I do have measurments.
The speedo housing I purchased is 2.075 inches diameter.
The speedo housing from my tranny is 1.935 inches diamter.

It's without question a turbo 400 pan. I have installed quite a few turbo 400 parts in this tranny including a manual valve body.

More information about the speedo housing.
My housing part number 1362077
The housing I was sent is 1362236.
Funny thing is I typed in my number and came across a few references to my number on the net concerning turbo 400 trans. Now I wonder if I was sent the wrong part, but I have two of these. I had forgotten that years ago I had ordered a speedo housing and gear, I then ordered another and then found the first housing I ordered. Both are wrong so something strange going on here, just need to get to the bottom of it so I can get the right part.

yep well i have had many 400s many built and a i built few over 30years and alot $$$ things done. but i never seen a smaller O.d on speed body ? should be a hydro tag on the side of the trans that should tell the year

pat,
Now I am convinced that both speedo housings or sleeves as they call them I was sent were wrong. I found a used tranny parts place out in Oregon and gave him my part number and he has the parts and said it's for a 400. Not sure why two different suppliers would have the housing wrong. Still tryin to get to the bottom of this.

Originally Posted by 73RS

pat,
Now I am convinced that both speedo housings or sleeves as they call them I was sent were wrong. I found a used tranny parts place out in Oregon and gave him my part number and he has the parts and said it's for a 400. Not sure why two different suppliers would have the housing wrong. Still trying to get to the bottom of this.

it would not be the first time i have picked up apart right number on box and wrong part in box all

It seems like I might have been sent a BOP TH 350 speedo sleeve. Things are starting to make more sense now.
I found the post below on another site.

The TH350 PN is 345215 superceded to 25513247 and it's different than the TH400.
The Chevy version is 7/8" diameter and the BOP version of the TH350 uses a larger one at 2.1" diameter.

The Chevy TH400 is 1.935" diameter and there is one for 34-39 teeth gears and one for 40-45 tooth gears.
I don't have the part number. You'll need to find a parts counter guy who knows how to find it.

Last time I did that search, it was called a "gear holder" in the computer. It comes in a Delco box and has the seals installed but may not have the outer O-ring. I think I got the O-ring at a local trans parts wholesaler and come to think of it they may also have the speedo gear "bullet" as some call it.

If you get the PN let us know and I'll post it in Best of tech. This one comes up about every six months or so.

Items in picture are from upper right going counter clockwise:
Drive gear
Driven Gear
Driven gear holder, sleeve or bullet
O ring

The TH400 gear holder has the gear range cast into to housing (34-39 or 40-45) it also reportedly fits the NP208 transfer case.

update
Part number is:
1362294 for the 34-39
1362293 for the 40-45

yep 350 is smaller

Now that I found the newer updated part number I Found a sleeve at amazon for 28 dollars free shipping too. Alot cheaper than the 60 dollar ones I saw.