Length of TH400/205 vs TH350/205

[6600DURAMAX]

Simple question. is the mounting point for the adapter plate that bolts the trans to the case located in the same location for the TH400/205 combo as the TH350/205 combe. In other words with the location of the transfercase crossmember be in the same location

thanks guys

[vtblazer]

Here's a good basic transmission info site for ya to browse.
Gives lengths and info down the page.

http://www.race-track.com/news.asp?TOPIC_ID=532

[6600DURAMAX]

Still really doesn't tell me what I need to know, that is, from the back of the motor to the mounting point of the adapter are the dimension the same and if not how much different?

thanks though

[gator2511]

When I converted to a th400 I had to get a new adapter, inputshaft and bearing and move the transfer case mount to the rear a few inches. I'll get a measurement later today. The shaft size and spline count on a 400 is different than a 350. I felt better about getting the transfer case machined and putting in a bigger bearing to handle the th400.

[6600DURAMAX]

Gator, where you ever able to get a measurement, sorry for the hassle but I have boxed the frame already up to the original crossmemeber and dont have a whole lot of room to move it.

thanks

[FormerMember]

Originally Posted by 6600DURAMAX

Gator, where you ever able to get a measurement, sorry for the hassle but I have boxed the frame already up to the original crossmemeber and dont have a whole lot of room to move it.

thanks

No, a Th350 and a Th400 are different lengths.

TH400 24.5" long
TH350 21.75" long

You're at least lucky in that you have to move the cross member back, not forward if you're putting in a TH400. If you're putting in a Th350, then you might want to re-think either another Th400 or at least a 700R4 which is 23.5" long.

[6600DURAMAX]

Grendel, I knew the cases themselves were a different length, I was just not for sure if the NP205 adaptor was made different so the crossmember didn't have to be moved?

[FormerMember]

Originally Posted by 6600DURAMAX

Grendel, I knew the cases themselves were a different length, I was just not for sure if the NP205 adaptor was made different so the crossmember didn't have to be moved?

Not one that's going to make up those differences.

They overall length difference is pretty much the distance it needs to move back, if you're using stock adapters.

Now you can get funky:
Use an aftermarket adapter and output to get shorter but you're disassembling or cutting the output shaft on your trans. There are 205 round pattern adapters that are an inch thick, vs the 2.5" and 4" thick factory ones. Seems like allot of work to me to avoid welding...

[gator2511]

Sorry to take so long but one of our grandbabies got sick and we were needed. O.K. I went from a Th350 to a TH400 and used a new Advance adapter. I had to move the rear cross member to the rear 2 3/4 inches. Let me know if you need anything else cause I'm home today and I'll get right back to you.

[FormerMember]

Originally Posted by gator2511

Sorry to take so long but one of our grandbabies got sick and we were needed. O.K. I went from a Th350 to a TH400 and used a new Advance adapter. I had to move the rear cross member to the rear 2 3/4 inches. Let me know if you need anything else cause I'm home today and I'll get right back to you.

This is the shortest adapter you can get.

The factory ones are longer.