Helpppp 71 GS 455 Torque converter may be bad??

Nickthenut1

New member
Joined
Jun 19, 2020
Messages
6
Reaction score
0
Points
1
Location
New Jersey
Buick Ownership
1971 GS 455
Hey guys. New here! So I have a 71 gs455 skylark. TH400. Cars been pretty good to me but recently was having some issues. Car started seemingly searching for a gear when lightly accelerating from 2-3rd. Second, third, second, third, back and forth until I would hit the gas a little harder, back down to second and then smoothly shift into third. With this new problem we noticed car acting almost as if it had a light stall reving up a bit higher than normal coming off idle or moving in reverse. Buddy of mine suggested a Trans Modulator, replaced that, fluid is clean and clear and smells good. Test drove and it seemed like the stall was still present but shifting issue went away. Buy then saw a buddy on our drive and decided to stop and do a standing burnout..would not break em loose at all after a few attempts (normally I can't get it to hook up at all and just blows em away). Newest thought process is that it may be my torque converter going bad? Open to hearing you guys thoughts! Appreciate the time.
 
When you were trying the burnouts did the engine rev and the car not move or the engine bogged, no increase in RPM?
You are aware that wide open throttle is controlled by a switch on the gas pedal that connects to a solenoid on the drivers side of the transmission case?
 
When you were trying the burnouts did the engine rev and the car not move or the engine bogged, no increase in RPM?
You are aware that wide open throttle is controlled by a switch on the gas pedal that connects to a solenoid on the drivers side of the transmission case?
Engine reved as it normally would just acting like it didn't have the power to break em loose and rpms wouldn't climb any higher. With my holley sniper kit I can see the throttle % and it still goes to wide open throttle
 
That doesn't sound like a transmission issue. As far as the Holley system is it tied in with the ignition system or you still have the stock Delco distributor?
I mentioned the kickdown switch, did you check if the wire is disconnected on either end?
Did you try the burnout by first manually shifting to first?
 
______________________________

Help support this site so it can continue supporting you!
That doesn't sound like a transmission issue. As far as the Holley system is it tied in with the ignition system or you still have the stock Delco distributor?
I mentioned the kickdown switch, did you check if the wire is disconnected on either end?
Did you try the burnout by first manually shifting to first?
Yeah it has the holley hyperspark full electronic ignition system as well. Wide open throttle works because once im moving, she rips. Just seemingly going from a stop it act like its stalled. Like when I used to mash it from a stand still it would blowww the tires away and now it feels like its slipping instead but engine still sounds the same
 
I really just wanted to know if that sounded like the symptoms of a failing torque converter like im being told before i replace it. Motor runs great, having a trans issue.
 
The motor doesn't rev from a standing start so why would that be a torque converter?

I specifically said that it does rev. Revs up as if it has a high stall converter in it but it does not. Almlst like its slipping before it fully engages. "reving up a bit higher than normal coming off idle or moving in reverse" "Engine reved as it normally would" "once im moving, she rips"
 
First, you need to check out V8buick.com That site caters to Buicks like yours.

When converters fail, the most common problem has to do with the stator. The stator is what makes a torque converter work, it redirects fluid inside the converter to multiply engine torque. The stator has a one way clutch that keeps it from rotating as long as the 2 halves (impeller and turbine) of the converter are rotating at different speeds. As the converter approaches coupling (2 halves rotating at the same speed), the stator is allowed to freewheel, and it no longer redirects fluid inside the converter.

There are 2 types of stator failure, constantly stuck, or constantly freewheeling. If the car accelerates poorly to 30-40 MPH, but has good pulling power at higher speeds, suspect a freewheeling stator at all speeds.

The second failure is a constantly stuck stator, the car will have good acceleration to a point, but top speed will be limited to 40-65 MPH, the engine will run hot, and gas mileage will be terrible.

You might have the 1st problem.

I have gone through several converters in my 70 GS. I originally had a switch pitch transmission with a 13" converter. Stall speeds were 2100/1100. I then went to a built 12" converter with 3200/1800 stall speeds.

http://www.buickperformanceclub.com/switchpitch.htm

I then went to a fixed pitch 400 with a very expensive 10" converter (1100.00) from Ultimate Converter Specialties. It performed OK, but it was just as heavy as my switch pitch converters. It really didn't improve my 60' times at the track. My current converter is a 9.5" fixed pitch converter from Tri Shield Performance. Tri Shield is run by Jim Weise. He is the owner of V8buick.com. He built my current engine, a Buick 455 bored and stroked to 470 CID. The motor made 602 HP/589 TQ, and powers my GS to mid 11 second 1/4 mile passes at 4200 lbs. I also have a Gear Vendors Overdrive in back of my THM400, so the converter not only needs to stall to get my car moving, but it also needs to be efficient enough to not slip excessively at highway speeds with a final drive ratio of 2.76. To say this is the best converter I have ever had in my car is an under statement. It weighs 25 lbs empty, a full 15 pounds lighter than my other converters. On the street, it feels like a stock converter until you jump on the gas. I can literally annihilate my tires from a 30 MPH roll. I can have my cake and eat it too. In addition, the converter comes with a lifetime warrantee. This converter was half the price of my Ultimate Converter, and it performs better. Mid 11 second car, and it can knock down 16 MPG on the open road. For me, it does not get much better than that.

Read about Jim's converters here,

TSP 9.5" Street/Strip converters- Lifetime warrantee!

Contact Jim at TSP here,

Tri-Shield Performance

And join V8buick and PM him. He knows Buick engines and is a lifelong Buick enthusiast.

IMG_1260.JPGTSP95converter2.jpg
 
Last edited:
First, you need to check out V8buick.com That site caters to Buicks like yours.

When converters fail, the most common problem has to do with the stator. The stator is what makes a torque converter work, it redirects fluid inside the converter to multiply engine torque. The stator has a one way clutch that keeps it from rotating as long as the 2 halves (impeller and turbine) of the converter are rotating at different speeds. As the converter approaches coupling (2 halves rotating at the same speed), the stator is allowed to freewheel, and it no longer redirects fluid inside the converter.

There are 2 types of stator failure, constantly stuck, or constantly freewheeling. If the car accelerates poorly to 30-40 MPH, but has good pulling power at higher speeds, suspect a freewheeling stator at all speeds.

The second failure is a constantly stuck stator, the car will have good acceleration to a point, but top speed will be limited to 40-65 MPH, the engine will run hot, and gas mileage will be terrible.

You might have the 1st problem.

I have gone through several converters in my 70 GS. I originally had a switch pitch transmission with a 13" converter. Stall speeds were 2100/1100. I then went to a built 12" converter with 3200/1800 stall speeds.

http://www.buickperformanceclub.com/switchpitch.htm

I then went to a fixed pitch 400 with a very expensive 10" converter (1100.00) from Ultimate Converter Specialties. It performed OK, but it was just as heavy as my switch pitch converters. It really didn't improve my 60' times at the track. My current converter is a 9.5" fixed pitch converter from Tri Shield Performance. Tri Shield is run by Jim Weise. He is the owner of V8buick.com. He built my current engine, a Buick 455 bored and stroked to 470 CID. The motor made 602 HP/589 TQ, and powers my GS to mid 11 second 1/4 mile passes at 4200 lbs. I also have a Gear Vendors Overdrive in back of my THM400, so the converter not only needs to stall to get my car moving, but it also needs to be efficient enough to not slip excessively at highway speeds with a final drive ratio of 2.76. To say this is the best converter I have ever had in my car is an under statement. It weighs 25 lbs empty, a full 15 pounds lighter than my other converters. On the street, it feels like a stock converter until you jump on the gas. I can literally annihilate my tires from a 30 MPH roll. I can have my cake and eat it too. In addition, the converter comes with a lifetime warrantee. This converter was half the price of my Ultimate Converter, and it performs better. Mid 11 second car, and it can knock down 16 MPG on the open road. For me, it does not get much better than that.

Read about Jim's converters here,

TSP 9.5" Street/Strip converters- Lifetime warrantee!

Contact Jim at TSP here,

Tri-Shield Performance

And join V8buick and PM him. He knows Buick engine and is a lifelong Buick enthusiast.

View attachment 23555View attachment 23556
Thank you so much!
 
Back
Top