th200-4r reverse on position 1 and no foward speed

[flat31]

Hi guys,
I'm French and I'm having a problem with my TH200-4R for my rod.(i doing 16000 miles before)
Two years ago, when I was returning from a concentrate at 106° Fahrenheit on the highway, I got a cloud of smoke while riding, and I stopped immediately.
I lost a little oil, but I was almost at the maximum, but I had no gears, either forward or reverse. I rebuilt the gearbox with parts from Art Car Transmission.
A rebuild kit (red disc, rings, all seals).
The oil pump is checked on a plate and is good (10-blade pump).
The forward drum is new.
The stator is new.
The converter is new. TCI242500.
There's a Transgo HD-2 .
Today, after 6 reassemblies, I still have the same problem: I have no forward gears, and in position 1 I have the reverse. (The rear wheels are raised.)
I don't know what to do except buy a rebuilt and tested gearbox, but the gearbox will cost me 5,000 euros including taxes, delivered to my home in 4 months.
I've been visiting this forum for months, and I've seen that you've managed to solve certain problems, so I'm giving it a try too.
In the reverse position, the wheels are locked as if I were in park. Idle pressures
P 63
R 100
N 65
D 64
D 64
2 62
1 60
At 1600 rpm
P 80
R 120
N 90
D 80
D 80
2 100
1 109
TV cable fully taut
P 110
N 110
D 110
D 90
2 90
1 90

 

[THensley]

this might help

 

[flat31]

thank's
i will look

 

[flat31]

The information in the manual is interesting, but I don't think it's the cable adjustment or the oil quality. I used high-quality oil.
I checked the air discs and pistons for proper operation. All the seals were changed second time, and all clearances are within the low tolerances specified in the ATSG review.
The valve body pistons were removed and are not locked.
In position R, the wheels are locked, and in position 1, I have reverse and nothing else.
Both parts of the oil pump were tested on a brand.
I think I overheated and that damaged something I can't see.

 

[THensley]

all your pressures are low.I will say Im no transmission builder and have no advice where to look I keep hopping TexesT would jump in.
I use that reference material from Extreme Automatic because I run his transmission.

 

[Rick the pool guy]

Did you check your transmission pressure after rebuild...if not most likely it failed due to inadequate pressure

 

[Anthony P]

I read you've rechecked things several times. So, I'm thinking simple issues like the o-ring on the filter neck or linkage mis-adjustment would have been discovered and explain why line pressures are low. And you did your air checks.

the line pressure preliminary check attachment below is from the GM service manual and is probably duplicative to what you already have. For reference, I attached the complete section 7 from the GM manual. Perhaps the charts can point you to additional areas to inspect.

there is also a dedicated facebook group dedicated to tech only. It's a private group run by a couple of turbo buick experts who work on these cars for a living. I'd suggest to join that group as well and ask for input before deciding to invest in shipping the trans to the USA for service. Link to the tech group below.

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[flat31]

Did you check your transmission pressure after rebuild...if not most likely it failed due to inadequate pressure

 

[flat31]

Oui, j'ai vérifié dans mon premier message. J'ai mis les pressions que j'ai après le remontage.

 

[flat31]

Yes, I checked it in my first message. I put the pressures I have after reassembly.

 

[flat31]

I read you've rechecked things several times. So, I'm thinking simple issues like the o-ring on the filter neck or linkage mis-adjustment would have been discovered and explain why line pressures are low. And you did your air checks.

the line pressure preliminary check attachment below is from the GM service manual and is probably duplicative to what you already have. For reference, I attached the complete section 7 from the GM manual. Perhaps the charts can point you to additional areas to inspect.

there is also a dedicated facebook group dedicated to tech only. It's a private group run by a couple of turbo buick experts who work on these cars for a living. I'd suggest to join that group as well and ask for input before deciding to invest in shipping the trans to the USA for service. Link to the tech group below.

The hydraulic diagnostics are the same as my ATSG, but yours includes hydraulic diagrams that will help me.
When I look at your line pressure chart, I see that my pressures are a little low, but in my ATSG, the pressures are for a 1990 200-4r gearbox, and yours are for a 1987 gearbox. Since my gearbox is from 1986, I'll use your chart as a guide.
Thanks for this information.

 

[Rick the pool guy]

Yes, I checked it in my first message. I put the pressures I have after reassembly.

Just saw pressure that you posted and that's way off...needless to say your transmission could be toast

 

[flat31]

Just saw pressure that you posted and that's way off...needless to say your transmission could be toast

I don't think it's burnt out since I replaced all the discs, clutches, seals, etc.

 

[TexasT]

those are some pretty low pressures as tested there. Who is doing this assembling? What does this pump look like in the cavity and the cover and what clearances are observed for the rotor and vanes? I like a stock seven vane pump and rotor but many get wrecked before you get the trans as the pump rings disintegrate cause catastrophic failure.
What size boost valve, reverse boost valve and spring are you using in this unit? Could be part or all of the prob with the pressures.
What does the fluid look and smell like? What was the observed clearance on those fwd clutches. Usually it doesn't make much difference but with your symptoms I would be looking at that forward clutch with no fwd gears.

 

[flat31]

those are some pretty low pressures as tested there. Who is doing this assembling? What does this pump look like in the cavity and the cover and what clearances are observed for the rotor and vanes? I like a stock seven vane pump and rotor but many get wrecked before you get the trans as the pump rings disintegrate cause catastrophic failure.
What size boost valve, reverse boost valve and spring are you using in this unit? Could be part or all of the prob with the pressures.
What does the fluid look and smell like? What was the observed clearance on those fwd clutches. Usually it doesn't make much difference but with your symptoms I would be looking at that forward clutch with no fwd gears.

I rebuilt the gearbox with a friend.
Everything was adjusted with a dial gauge.
The pump has 16,000 miles and has 10 vanes (the vanes are unmarked and are mounted the right way around) and its housing is unscratched. Both pump bodies have been run over a marble and have no scratches.
The reverse boost, boost valve, and spring are from the Transgo HD-2D kit.
When I broke down, the oil was red and didn't smell burnt.
During disassembly, no discs were burned or broken.
The forward clutch clearance is adjusted to 0.032".