The official,unofficial guide to transfer case adapters
 

"What does this adapter fit or what adapter do I need to run transfer case X behind transmission Y" is a commonly asked question on this board and others that I frequent.This is a guide to help identify what parts you have or will need when swapping transmissions and cases.

Starting in around 1970ish until around 1977 the Th350/205 adapters used a center support bearing around the drive sleeve to hold it in place.
http://i59.photobucket.com/albums/g3...ale/009-17.jpg
The sleeve had a step cut in it to accommodate the bearing,whereas the later style didn't.
Early style on the left,later on the right.
http://i59.photobucket.com/albums/g3...20pics/008.jpg


The 78ish to 80 Th350/Np205 adapters are identical to the earlier style with the exception of the sleeve and bearing.All Th350/205 will have a four bolt pattern on the trans side.
http://i59.photobucket.com/albums/g3...20pics/084.jpg

And racetrack or figure eight pattern on the case side.
http://i59.photobucket.com/albums/g3...20pics/085.jpg

During that time GM also offer the 203 fulltime case behind the TH350's and they took a different adapter.

Trans side.
http://i59.photobucket.com/albums/g3...ics/8c3a_1.jpg

Case side.
http://i59.photobucket.com/albums/g3...ics/8d51_1.jpg

The Th400 adapters came in four different styles depending on the application.
The 400/205 adapters were either the figure eight/racetrack pattern up until about 1984,or the later round pattern used until around 91 when the body style changed on the 1-tons.

Figure 8/race tack pattern (trans side).
http://i59.photobucket.com/albums/g3...ale/005-19.jpg

Case side.
http://i59.photobucket.com/albums/g3...ale/007-15.jpg

The late style round pattern adapter.

Trans side.
http://i59.photobucket.com/albums/g3...s/100_3345.jpg

Case side.
http://i59.photobucket.com/albums/g3...s/100_3348.jpg

Re: The official,unofficial guide to transfer case adapters
 

The 81ish-87 3/4 ton's with the Th400 trans used a different adapter.It is shorter/thinner than the 400/205 adapter's and has no provisions for a shifter to be bolted on the side.

Trans side.
http://i59.photobucket.com/albums/g3...0pics/4002.jpg

Case side.
http://i59.photobucket.com/albums/g3...20pics/400.jpg

The 400/208 combo's used the Mil CUCV pickup's were the same as the civilian versions but use a taller or longer adapter.Otherwise they are the same as the civ version.
http://i59.photobucket.com/albums/g3...Picture193.jpg

The 400/203's used one style and it was completely different from the others.
Trans side.
http://i59.photobucket.com/albums/g3.../pics525-1.jpg
Case side.
http://i59.photobucket.com/albums/g3...s/100_3170.jpg

In about 1981 GM starting usin the 208's behind the Th350's.It was only a 1-2 year deal until the 700R4's came out.The 700 and 350's both different adapters.

The Th350/208 adapter,trans side.
http://i59.photobucket.com/albums/g3...s/100_3172.jpg

By 1983 they were using the 700's and it required another adapter.

Trans side.
http://i59.photobucket.com/albums/g3...e/100_3171.jpg

Re: The official,unofficial guide to transfer case adapters
 

The SM465 four speeds used four different adapters.The 465/Rockwell 221 adapter was the first.(I will post at a later date).

The second was the 465/205 adapter used from about 1972ish to 1980.

Trans side.
http://i59.photobucket.com/albums/g3...cture192-1.jpg

Case side.(again the racetrack/figure eight pattern)
http://i59.photobucket.com/albums/g3...sale/023-5.jpg

Around 1973 until 1975 they offered the 203 behind the 465.This is the only pic I have at this time.

http://i59.photobucket.com/albums/g3...s/100_4047.jpg

The 3 speed sagianw transmissions were offered with a 205 behind them as well.
Trans side.
http://i59.photobucket.com/albums/g3...20pics/028.jpg

Case side.
http://i59.photobucket.com/albums/g3...20pics/019.jpg



In 1981 they went to the NP208 and for the most part got away from the 205's except in the 1-tons.The 465 adapters changed again with the case change.

Trans side.
http://i59.photobucket.com/albums/g3...Picture192.jpg

Case side.
http://i59.photobucket.com/albums/g3...Picture191.jpg

Around 1986 GM went to the round pattern 205's and changed the adapters also.

Trans side.
http://i59.photobucket.com/albums/g3...ale/007-23.jpg

Case side.
http://i59.photobucket.com/albums/g3...ale/006-27.jpg

The late 465/205 adapter looks alot like the 465/208 adapter but the 208 adapter will work on a 205 due to it not having any provisions for a shifter(notch on the flange and threaded insert on side.
http://i59.photobucket.com/albums/g3...ale/005-30.jpg


Now for the disclaimer.I am not an expert nor do I claim to be.The dates are not exact,give or take a year or two, and this is not to say that newer/older parts have been swapped in.These are merely my observations from years of swappin/buyin/sellin and usin these parts.

Re: The official,unofficial guide to transfer case adapters
 

Good idea! I'd like to add that of the 465/ 205 combos, the later "round pattern" is IMO the best. It uses a female input like the TH400 setup. No coupler to wear, less "clink clank" on accel/ decel and far stronger. The old coupler type can can split or shear the splines off with big HP and abuse.

Re: The official,unofficial guide to transfer case adapters
 

I have pulled the old 10 spline sleeve's off and the splines on the trans output have almost a razors edge on em.The later is a lot better design,just harder to come by.

Re: The official,unofficial guide to transfer case adapters
 

Do you need pics of the Rockwell T221 to SM465 adapter? I'll take some good ones for you if you do. I also have a good pic with a side by side comparison of the NP205 sleeve and the Rockwell T221's sleeve.

Re: The official,unofficial guide to transfer case adapters
 

Here are some I have. #1 is the transmission side of the 465/221 adaptor

http://i14.photobucket.com/albums/a3...y/DSC02983.jpg

this is the transfer case side

http://i14.photobucket.com/albums/a3...y/DSC02984.jpg

the side cover

http://i14.photobucket.com/albums/a3...y/DSC02985.jpg

and then I had this shot saved of the 32 spline 465/205. This isn't mine, I forget where I found the pic.

http://i14.photobucket.com/albums/a3...ny/465_205.jpg

Re: The official,unofficial guide to transfer case adapters
 

Lookin`good for a FAQ thread for sure.How about transfer case differences for each transmission?Like spline counts and differences in shaft lengths.

Re: The official,unofficial guide to transfer case adapters
 

This has been long overdue...some great info here.

Re: The official,unofficial guide to transfer case adapters
 

Here is a comparison of the measurements of the SM465/Rockwell T221 combo and the SM465/NP205 combo (the NP205 is a 70's vintage with a yoke style rear output.)

http://yukon.b0xen.us/69chevy/rockwellinfo.jpg

http://yukon.b0xen.us/69chevy/np205info.jpg

And here are some pics of the coupler/sleeve differences. Both couplers are for mating to the SM465.

http://yukon.b0xen.us/69chevy/couplers1.jpg

http://yukon.b0xen.us/69chevy/couplers2.jpg

http://yukon.b0xen.us/69chevy/couplers3.jpg

The first pic makes the one coupler's diameter look alot bigger, but it is actually just a bit bigger.

And a note, the 3 speed manual/Rockwell coupler is longer than the SM465/Rockwell coupler and can be cut down to be used if you were to swap from the 3 speed manual to the SM465 but still staying with the Rockwell transfer case.

Re: The official,unofficial guide to transfer case adapters
 

I spent about 3 hours taking,gathering,and posting pics yesterday and thought I had em on my comp but I didnt.By the time I realized I didnt it was four degrees outside and I wasnt goin back out.:waah:

Thanks for the pics.


I'm hoping to start on my doubler this coming week and will try to get some pics and work on it.

Does anybody have any pics of the TH350/Dana adapter ???? The one used before the 205's.That is the only adapter I have never had one of.

Re: The official,unofficial guide to transfer case adapters
 

Excellent information. This will be very helpful in my saginaw to sm465 conversion. Thank-you 1-tonmudder!

Re: The official,unofficial guide to transfer case adapters
 

I got my late style 465/205 adapter today so I added that info.

Re: The official,unofficial guide to transfer case adapters
 

Old thread--does anyone know where this information (with pictures) can be found today?