TH2004R lock-up
Thread Starter
Navigator
Joined: Feb 2015
Posts: 9
Likes: 0
From: Stjoerdal Norway.
TH2004R lock-up
Hi,
I installed a TH2004R. Installation went well and the transmission are working well. Until lock-up.
When driving the shifts are smooth and nice, both up and down. However, I feel that the lock-up engages to early. When driving steady and reaching about 30-35 mph 4th engages, and lock-up appears immediately. Engine RPM falls to 6-700.
It locks when switching to fourth at “any” speed except at WOT. In addition, I feel that I need to “trigger” disengage by light tap on the brake pedal. It kind of “hang in” too long. Does not downshift either. However, it disengage/downshift before the engine stalls.
Would appreciate if any of you have any tip on what could be the fix or problem. I’m thinking of a manual engage/disengage, also recommendation on such solution would be welcome
I installed a TH2004R. Installation went well and the transmission are working well. Until lock-up.
When driving the shifts are smooth and nice, both up and down. However, I feel that the lock-up engages to early. When driving steady and reaching about 30-35 mph 4th engages, and lock-up appears immediately. Engine RPM falls to 6-700.
It locks when switching to fourth at “any” speed except at WOT. In addition, I feel that I need to “trigger” disengage by light tap on the brake pedal. It kind of “hang in” too long. Does not downshift either. However, it disengage/downshift before the engine stalls.
Would appreciate if any of you have any tip on what could be the fix or problem. I’m thinking of a manual engage/disengage, also recommendation on such solution would be welcome
Melting Slicks
Joined: Feb 2007
Posts: 2,136
Likes: 62
From: West Kingston RI
I am not an expert but the first thing that comes to mind is did you hook up and adjust the TV cable check out this site for some ideas. http://www.cpttransmission.com/tech_tvcable.htm
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
i had to install a controller from B&M. it locks/unlocks converter at what ever speed you set it at.
automatically. mines works really well. i have mine set at 65 mph....
http://www.summitracing.com/parts/bmm-70244
https://www.corvetteforum.com/forums...ntrol-box.html
automatically. mines works really well. i have mine set at 65 mph....
http://www.summitracing.com/parts/bmm-70244
https://www.corvetteforum.com/forums...ntrol-box.html
Last edited by speedreed8; Feb 2, 2015 at 03:23 PM.
Thread Starter
Navigator
Joined: Feb 2015
Posts: 9
Likes: 0
From: Stjoerdal Norway.
i had to install a controller from B&M. it locks/unlocks converter at what ever speed you set it at.
automatically. mines works really well. i have mine set at 65 mph....
http://www.summitracing.com/parts/bmm-70244
https://www.corvetteforum.com/forums...ntrol-box.html
automatically. mines works really well. i have mine set at 65 mph....
http://www.summitracing.com/parts/bmm-70244
https://www.corvetteforum.com/forums...ntrol-box.html
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Unless you have a valve body from a Buick turbo regal, the 4th gear shift is low at light throttle, the BR valve body doesn't shift to OD till 43 mph. Some choices are a conrtoller like speedreed uses or just keep the shifter in 3rd till you get out of town, or a cut-off switch for the lock-up.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If your rear axle is under 3.36, you need to put the transmission in 3rd (instead of D) when you will be running at less than about 45mph. Otherwise, the lockup will engage and you will be bogging down. It's not that big of a deal. Under 45mph, put it in '3'; over 45mph, put it in 'D'. That'll solve your problem.
[Guessing you have a 3.08 gear in back...]
[Guessing you have a 3.08 gear in back...]
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Team Owner
Joined: May 2005
Posts: 31,497
Likes: 1,313
From: Huntsville AL
'75 made a good point. Did your 200 4R come from a Buick Grand National?
Apparently there is a difference in these, and some of the 200 4R don't seem to work quite as well in these applications as the Buick GN 200 4R.
I am real interested in this discussion. I have a rebuilt 200 4R out of a GN in my garage. I am planning on putting it in my 56 Bel Air when I put a later (than 1956) engine in the car.
Apparently there is a difference in these, and some of the 200 4R don't seem to work quite as well in these applications as the Buick GN 200 4R.
I am real interested in this discussion. I have a rebuilt 200 4R out of a GN in my garage. I am planning on putting it in my 56 Bel Air when I put a later (than 1956) engine in the car.
Thread Starter
Navigator
Joined: Feb 2015
Posts: 9
Likes: 0
From: Stjoerdal Norway.
'75 made a good point. Did your 200 4R come from a Buick Grand National?
Apparently there is a difference in these, and some of the 200 4R don't seem to work quite as well in these applications as the Buick GN 200 4R.
I am real interested in this discussion. I have a rebuilt 200 4R out of a GN in my garage. I am planning on putting it in my 56 Bel Air when I put a later (than 1956) engine in the car.
Apparently there is a difference in these, and some of the 200 4R don't seem to work quite as well in these applications as the Buick GN 200 4R.
I am real interested in this discussion. I have a rebuilt 200 4R out of a GN in my garage. I am planning on putting it in my 56 Bel Air when I put a later (than 1956) engine in the car.
Team Owner
Joined: May 2005
Posts: 31,497
Likes: 1,313
From: Huntsville AL
I am assuming that BTO is not Bachman Turner Overdrive? Yep, definitely showing my age.
Seriously, I am not familiar with BTO, but if you bought it from them, they should be able to tell you what it came out of, or at least what specs / valve body is in it?
Seriously, I am not familiar with BTO, but if you bought it from them, they should be able to tell you what it came out of, or at least what specs / valve body is in it?
Thread Starter
Navigator
Joined: Feb 2015
Posts: 9
Likes: 0
From: Stjoerdal Norway.
Thnx guys for good advices. As I see it, I have these options:
1. Install a controller, or
2. Keep it in 3rd at less than about 45mph, or
3. Change the valve body (if it’s from a GN)
1. Install a controller, or
2. Keep it in 3rd at less than about 45mph, or
3. Change the valve body (if it’s from a GN)
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you do not have some kind of 'controller' on the trans lockup (L/U) feature, that is a problem in itself. The L/U clutch results in the converter part of the trans being bypassed...there is a direct drive link from the engine output to the gear box, without a fluid coupling in between. In essence, when in lockup, it drives like a manual transmission vehicle: if your engine rpm's aren't high enough, it will buck and jerk around. It is also important to know that the L/U clutch in an auto tranny is NOT designed to handle much torque. If the L/U clutch is ON and you stab the gas, you can easily damage or destroy your L/U clutch.
These are reasons why a controller is a useful device; it makes the needed decisions [for you] as to WHEN the L/U clutch should be ON or OFF and will automatically handle those functions. If you do not want to spend the money for a controller, at least put a cut-off switch in the circuit and then ONLY turn on the L/U clutch when you really need it...long-term cruising on the highway or at 45 mph or higher. The benefits of L/U clutch use in city/traffic situations is minimal.
These are reasons why a controller is a useful device; it makes the needed decisions [for you] as to WHEN the L/U clutch should be ON or OFF and will automatically handle those functions. If you do not want to spend the money for a controller, at least put a cut-off switch in the circuit and then ONLY turn on the L/U clutch when you really need it...long-term cruising on the highway or at 45 mph or higher. The benefits of L/U clutch use in city/traffic situations is minimal.
Racer
Joined: Feb 2002
Posts: 378
Likes: 19
Have been using a 2004R in my daily driver, '79 Malibu. Used the Painlesswiring 60109 lock-up kit. The kit includes a new clutch solenoid and 4th gear pressure switch. Also included is a brake switch and a vaccum switch that disconnects the lock-up when engine is under load. Even with the kit installed, I still installed a on/off switch. Under normal crusing I lock the clutch at 45 mph.