Well I'm phukd. Th400 lost 3rd

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da_raabi

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Well thats it. I'm done. Finished the last few things last night. Now I've just got to get it back in the truck and pray that it works!

Here it is!
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The blown clutch friction I found:
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Extra Parts???
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74 Shortbed

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Cool...:waytogo:
 

1987 GMC Jimmy

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Ahh, it's gonna be great. Looking forward to the good news.
 

DoubleDingo

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Sweet deal! Can't wait to hear how it performs.
 

74 Shortbed

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Fantastic...
 

HotRodPC

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Well I'm not going to confirm or deny that. I don't like bashing companies on forums as I do I realize that this may be an isolated case. I was otherwise impressed with the parts I received, and he is trying to make it right. I just don't understand how this kind of thing could happen. Once again there should be a package arriving today with new intermediate frictions. Hopefully there is nothing wrong with them and my wife can go ahead and get them soaking for me.

Oh well. No biggie. As long as the truck works when this is all over with I'll be happy.
You don't have to bash a company, but really, you should say so. Not to trash them, but as to help out fellow members here. That's what we do here. We try to have each other's back and if we had a bad experience, then at least share a bit of it, so we know to use caution or make our own choice as to if we will purchase there or not. I know @crazy4offroad had a very bad experience at Randy's Ring and Pinion, so I used caution, ordered a part from them, didn't have a problem but I damn sure I was getting the correct **** so I didn't have to go through what he did. I have not had any bad experiences with transmissionpartsUSA.com. Maybe I've been lucky so far.

I know of many parts I won't buy from LMC, but some I will by reviews and feedback I've gotten here.

Also, it seems they admitted their screw up and at least making an attempt to make it right. No company is perfect, so I'd like to know what company will at least make an attempt to make it right if they do screw up. IMO, that's a good thing, so I don't take that as bashing a company at all. That's a company stepping up when they fugg up.
 

HotRodPC

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On another note, glad to hear you got it done and it's shifting. I remember the feeling when I built my 1st ever Th350, installed it. Holding my breath and how it felt when it had Reverse to get outta the driveway, then 1st to 2nd shift and then 2nd to 3rd shift. Like a kid on Christmas morning. Got back home from the test ride. A little adjustment on the vac mod, a little adjustment on the detent cable to stetch out the shift points a little, another ride, and little more adjustment on the detent cable and then it was perfect and all out about giving it hell.
 

da_raabi

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You don't have to bash a company, but really, you should say so. Not to trash them, but as to help out fellow members here. That's what we do here. We try to have each other's back and if we had a bad experience, then at least share a bit of it, so we know to use caution or make our own choice as to if we will purchase there or not. I know @crazy4offroad had a very bad experience at Randy's Ring and Pinion, so I used caution, ordered a part from them, didn't have a problem but I damn sure I was getting the correct **** so I didn't have to go through what he did. I have not had any bad experiences with transmissionpartsUSA.com. Maybe I've been lucky so far.

I know of many parts I won't buy from LMC, but some I will by reviews and feedback I've gotten here.

Also, it seems they admitted their screw up and at least making an attempt to make it right. No company is perfect, so I'd like to know what company will at least make an attempt to make it right if they do screw up. IMO, that's a good thing, so I don't take that as bashing a company at all. That's a company stepping up when they fugg up.

Ok, now I've got some time I'll fill in the details.

The place I got my parts was, in fact, transmissionpartsusa.com. Towards the end it was starting to get pretty friggen silly, what with all the issues, but to their credit they did overnight parts to me 3 times, no questions asked. So they did try extremely hard to make sure I was satisfied - at their (probably significant) expense. Would I go back? Maybe, but with caution. Again, I don't like calling them out - however they did try very hard in the end to make it right. Can't fault them for that.


As to the trans. I drove it a few times Saturday and things seemed ok. Pressure was a solid 150psi shifting through all gears with brakes applied in the driveway. I think that's good?

The only issue I have is one that existed prior to the rebuild. When accelerating at WoT, the 1-2 shift is very laggy. You can tell it is trying to shift, but it's like it hits neutral for a couple of seconds and sends the engine RPM sky-high (signified by a squealing belt - I don't have a tach). The 2-3 shift is very very VERY nice. Right where I want it firmness/RPM wise. The 1-2 issue was present prior to rebuild too.

I did install a new Vac modulator - the red band type that is adjustable. All I did was install it, I did not adjust it. Vacuum is connected with new hose at both ends (engine and modulator).

I am suspecting a governor issue as this only seems to happen at heavy/wide open throttle. I attempted to measure the valve clearances per the ATSG manual during rebuild and found they were incorrect - but could not figure out what to do about it - so I left it alone. See pic below of ATSG instruction page on this issue. Could this be causing my late/laggy/soft 1-2 WoT shift?

Any help would be much appreciated - but please oh PLEASE do not tell me I need to drop the transmission. I'll just park it and go drop a dump instead...:dancingpoop:

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da_raabi

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So I turned in the modulator about 1.5 turns, which helped firm up the shifts a touch and brought the shift points up too. I still have the 1-2 shift lag problem at WoT, but it only happens at WoT from a standstill. The truck does not like to go down into 1 almost any other time, so it does not really bother me too much. Pretty much only matters if I'm drag racing. Which I don't do lol. All other shifts are PERFECT!!!

I did pick up a nasty driveline vibration at 65mph+. I'm thinking I may not have got the carrier bearing on the driveshaft where it wants to be. So I still need to look into that. Below 65 its not too bad.
 

Jrgunn5150

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So I turned in the modulator about 1.5 turns, which helped firm up the shifts a touch and brought the shift points up too. I still have the 1-2 shift lag problem at WoT, but it only happens at WoT from a standstill. The truck does not like to go down into 1 almost any other time, so it does not really bother me too much. Pretty much only matters if I'm drag racing. Which I don't do lol. All other shifts are PERFECT!!!

I did pick up a nasty driveline vibration at 65mph+. I'm thinking I may not have got the carrier bearing on the driveshaft where it wants to be. So I still need to look into that. Below 65 its not too bad.


There may be some bore wear in the governor or something.
 

da_raabi

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I'm definitely leaning towards this being a governor issue. Everything seems to point in that direction. I may pull it out and disassemble it for inspection and cleanup, re-gear it and see how it goes. A gear kit is only about $5. A new governor is around $60, but then I'm not entirely sure which one is correct for my application.

Anybody have any idea how to find/replace the governor on a TH400? I thought they were model/setup specific for each vehicle.
 

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