Refreshing Gunny the thread.

[cucvrus]

How about the modulator? is it getting vacuum? And is the hose tight going into the modulator? And being that you had the transmission out are you sure the metal line that runs down is not cracked or kinked. Check that also. I always take my CUCV's to a friend to get the vacuum modulator adjusted. That friend died during the pandemic and finding trustworthy mechanics that know older stuff is getting hard to do. I can figure it out sometimes it takes a while and several adjustments of the VCV on the injection pump. That VCV could be bad also. Take Care and Good Luck.

 

[ssdvc]

Gunny, I went through this not to long ago. After replacing the vacuum pump (didn't need to, it was fine), the vacuum control valve (top of the IP and it wasn't working as it should), the vacuum modulator (at the trans, and I didn't need to it was fine) I finally found out I had a bad rubber vacuum line from the hard line to the vacuum modulator. I replaced all the rubber vacuum lines (and made sure they were tight on the metal lines) and all was fine.

It is a hunt and pec kinda thing, but check those items. Since she seems to be shifting fine (and I thought you did hit third, as the RPM's didn't seem excessive), I think you can rule out the modulator and the VCV as problems. That said, I'm no master mechanic, so maybe someone else with more experience can chime in with better advise.

 

[GunnyM1009]

Vacuum is fine now that last photo was vacuum at the Trans metal tube. The rubber line between the metal line and the modulator is new as is the modulator.

 

[GunnyM1009]

When put in drive it seems to shutter or slip as I'm accelerating then it won't shift. I'm starting to think it may be the torque converter. It's a new reman torque converter from Autozone. Is it possible or am I way off base.

 

[cucvrus]

At this time, I would not speculate. I would take it to a competent transmission shop and have it diagnosed. Was the transmission rebuilt by a skilled knowledgeable person? I hope you didn't buy a used transmission that was missing a torque converter and install it. Burnt clutch material causes slippage in the TH400 transmission. CUCVRUS Repair Projects | Page 18 | SteelSoldiers Here are internal parts from a customer's TH400 from an M1009 with about 50K miles on it. It would get hot and spit fluid and slippage was the cause. I have several CUCV TH400 transmissions and I would never just put 1 in and run it. I use them as cores for rebuilding. And I don't rebuild them. I pay to have them rebuilt. Good Luck. I hope it all works out for you. These old trucks can be a real budget breaker. But fixing things right and spending the coin up front makes them reliable and I like reliability.

 

[GunnyM1009]

At this time, I would not speculate. I would take it to a competent transmission shop and have it diagnosed. Was the transmission rebuilt by a skilled knowledgeable person? I hope you didn't buy a used transmission that was missing a torque converter and install it. Burnt clutch material causes slippage in the TH400 transmission. CUCVRUS Repair Projects | Page 18 | SteelSoldiers Here are internal parts from a customer's TH400 from an M1009 with about 50K miles on it. It would get hot and spit fluid and slippage was the cause. I have several CUCV TH400 transmissions and I would never just put 1 in and run it. I use them as cores for rebuilding. And I don't rebuild them. I pay to have them rebuilt. Good Luck. I hope it all works out for you. These old trucks can be a real budget breaker. But fixing things right and spending the coin up front makes them reliable and I like reliability.

I rebuilt the Trans following a manual step by step. It is possible I screwed something up.

 

[cucvrus]

I guess at this point anything is possible. Did you replace any of the clutch discs? I worked on vehicles all my life and auto transmissions were always considered a specialty. In the GM dealership I worked in we all specialized in certain areas. Transmissions was always 2 guys area of expertise. I often did the R &R of the transmission, and they did the internal work. I wish you luck. It could be simple it could be internal I don't know enough to elaborate pro or con.

 

[GunnyM1009]

I guess at this point anything is possible. Did you replace any of the clutch discs? I worked on vehicles all my life and auto transmissions were always considered a specialty. In the GM dealership I worked in we all specialized in certain areas. Transmissions was always 2 guys area of expertise. I often did the R &R of the transmission, and they did the internal work. I wish you luck. It could be simple it could be internal I don't know enough to elaborate pro or con.

It's all good I'll figure it out. Every friction, steel, bearing, and bushing was replaced in it. It was a complete rebuild. I just ordered another torque converter to see if that's the issue. I know everyone one can make mistakes but I was very meticulous while rebuilding that Trans. I just don't feel like it's something I did. We will find out when the new converter gets here. If it's not the converter I will probably just save up the money to take it to a professional and scratch TH400 rebuilding off the list of things I can do properly.

 

[GunnyM1009]

So after trying multiple things like checking the vacuum, modulator, governor etc. I came to the conclusion I missed something or did something wrong on the rebuild. To my dismay the transmission has to come back out. I'm not giving up though. I'm going to go back through it and see if I can find my mistake.

 

[cucvrus]

Governor?

 

[GunnyM1009]

Governor?

This, there is a valve inside. The weights on one end open up as it spins which in turn moves the valve. It has a lot to do with shift points.

 

[GunnyM1009]

I just wanted to give an update on the transmission situation. I can't find anything wrong with my rebuild so instead going in and out with it a bunch I am just going to save up and get a Monster Transmissions TH400 to put in him. I should be able to order it around May of 2023. At least it will be a professional job with a warranty.

 

[cucvrus]

Turbo 400 TH400 Transmission 4x4 Performance Super Duty 4WD, turbo 400 monster transmission, Racing Th400, Race Th400, Racing Turbo 400

You could have the original transmission overhauled for 1/2 the price. Happy Holidays. That would be a good price if that was in the truck and out with labor and all.