Need Help On Tranny Conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gator2511 · 03-22-2005, 07:01 PM

I bought a th400, Gear Vendors O.D., and was buying the adapter from Advance Adapters to connect the th400 to the 205 transfer case when they said it couldn't be done! My 205 transfer case is made for a four speed standard tranny. They say nobody has an adapter for that. I'm told I'll have to find a rebuildable 205 transfer case made to fit an automatic or convert to a stick shift. Have any of you guys run into this before? I'd really like to go with the th400 so I can tow my travel trailer with it. Don't know what to do now!

The truck is a 72 short wheel base fleetside 1/2 ton.

**kwmech** · 03-22-2005, 09:37 PM

I do it all the time, you have to buy a turbo 400 input gear for the 205, the correct bearing and the snap rings. Then completely disassemble the 205 and have the case machined for the bigger bearing.

gator2511 · 03-22-2005, 09:47 PM

My local boys and the guys out in Kalifornia don't know about this. I believe you though. I know it can be done. What kind of ball park figure are we talking about for parts and the machine shop cost? No offense intended. Just kidding. The big boy adapter company in calif. had no help for me.

**kwmech** · 03-25-2005, 01:20 AM

Input gear--about 135. bearing about 50. snap rings 15. complete gasket and seal kit 35. The machine shop I use has done about 20 cases for over the last couple of years and charges me 50. Takes about 20 minutes for me to disassemble, 20 minutes in the hot tank. further cleaning and reassembly about 1-2 hours--depending on filth and the amount of detailing and painting.

gator2511 · 03-26-2005, 12:11 PM

Well, Advance Adaptor does have a kit for this after all. You just have to get the right sales rep. Thanks for the info on this. Looks like the big problem is going to be finding a machine shop to do the work. Most of them are super busy and don't seem to want to take the time to talk to me about it. I guess when I have the case in my hands they will be better to talk to.

03-22-2005, 07:01 PM	#1
gator2511 Registered User Join Date: Mar 2005 Location: tampa florida Posts: 776	Need Help On Tranny Conversion I bought a th400, Gear Vendors O.D., and was buying the adapter from Advance Adapters to connect the th400 to the 205 transfer case when they said it couldn't be done! My 205 transfer case is made for a four speed standard tranny. They say nobody has an adapter for that. I'm told I'll have to find a rebuildable 205 transfer case made to fit an automatic or convert to a stick shift. Have any of you guys run into this before? I'd really like to go with the th400 so I can tow my travel trailer with it. Don't know what to do now! The truck is a 72 short wheel base fleetside 1/2 ton.

03-22-2005, 09:47 PM	#3
gator2511 Registered User Join Date: Mar 2005 Location: tampa florida Posts: 776	My local boys and the guys out in Kalifornia don't know about this. I believe you though. I know it can be done. What kind of ball park figure are we talking about for parts and the machine shop cost? No offense intended. Just kidding. The big boy adapter company in calif. had no help for me. Last edited by gator2511; 03-22-2005 at 10:28 PM.

03-22-2005, 09:37 PM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,650	I do it all the time, you have to buy a turbo 400 input gear for the 205, the correct bearing and the snap rings. Then completely disassemble the 205 and have the case machined for the bigger bearing.

03-25-2005, 01:20 AM	#4
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,650	Input gear--about 135. bearing about 50. snap rings 15. complete gasket and seal kit 35. The machine shop I use has done about 20 cases for over the last couple of years and charges me 50. Takes about 20 minutes for me to disassemble, 20 minutes in the hot tank. further cleaning and reassembly about 1-2 hours--depending on filth and the amount of detailing and painting.

03-26-2005, 12:11 PM	#5
gator2511 Registered User Join Date: Mar 2005 Location: tampa florida Posts: 776	Well, Advance Adaptor does have a kit for this after all. You just have to get the right sales rep. Thanks for the info on this. Looks like the big problem is going to be finding a machine shop to do the work. Most of them are super busy and don't seem to want to take the time to talk to me about it. I guess when I have the case in my hands they will be better to talk to.



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