Symptoms of broken sprague in converter

art leong · 08-27-2011, 04:15 PM

What would the symptoms be from a broken sprague in the converter?

Rick Shirey · 08-27-2011, 05:18 PM

Art, I had this problem several times and the best indicator is the rpms dropping below converter flash rpm aftergear change.

Mark Yacavone · 08-27-2011, 05:27 PM

Art, With a broken sprag, the stator no longer functions as such, therefore a torque converter reverts to a just a fluid coupling.
Very low stall speed but a great top end!

art leong · 08-27-2011, 05:58 PM

I think I've been fighting the programming on the ECU for 2 months for nothing.
When I put the car in gear (1st) with the brakes on and come up against the converter (around 2200) the motor goes crazy and usually stalls.
When I don't hold the brake (on jack stands) It revs normally, but when I lock up the brakes it stalls.
I've been trying to tune the lower rpms but no changes seem to make any difference.
I hurt the trans last year but didn't think I hurt the converter.
The last time out the car left like a stone With the rpms going from 2700 to 3300 up and down for about 100 feet then it cleared up and ran normal. Short time was off by 6 tenths (not a typo). Car made plenty of horsepower and torque on the chassis dyno, So I thought it had something to do with the low end tune.

Mark Yacavone · 08-27-2011, 08:32 PM

A roller sprag can lock and slip intermittently , but it usually won't do that for long until it quits applying altogether.

Alan Warman · 08-29-2011, 12:48 PM

This might be the problem I had all last year. I built a old school TH200 for my car, the front pump uses power guild splines. Had a converter built for it. When I first but it together the converter would brake stall to 3200 and flash to 4800 but it had no high gear. So after talking to several people I bought a Billy Lynn valve body and Billy walked me though the build. Well it had high gear now but the converter would only brake stall to about 2200 and flash to 4200. The car would run dead on times and had 1 to 2 more mph than it should have for the ET that it ran. Does this sound like my problem.

08-27-2011, 04:15 PM	#1
art leong VIP Member Join Date: Dec 2001 Location: Richmond Hill, Georgia Posts: 2,003 Likes: 0 Liked 1 Time in 1 Post	Symptoms of broken sprague in converter What would the symptoms be from a broken sprague in the converter? __________________ Art Leong 2095 SS

08-27-2011, 05:18 PM	#2
Rick Shirey Junior Member Join Date: Apr 2003 Posts: 53 Likes: 0 Liked 0 Times in 0 Posts	Re: Symptoms of broken sprague in converter Art, I had this problem several times and the best indicator is the rpms dropping below converter flash rpm aftergear change.

08-27-2011, 05:27 PM	#3
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,417 Likes: 2,582 Liked 4,453 Times in 1,694 Posts	Re: Symptoms of broken sprague in converter Art, With a broken sprag, the stator no longer functions as such, therefore a torque converter reverts to a just a fluid coupling. Very low stall speed but a great top end! __________________ We are lucky we don't get as much Government as we pay for..... Will Rogers

08-27-2011, 05:58 PM	#4
art leong VIP Member Join Date: Dec 2001 Location: Richmond Hill, Georgia Posts: 2,003 Likes: 0 Liked 1 Time in 1 Post	Re: Symptoms of broken sprague in converter I think I've been fighting the programming on the ECU for 2 months for nothing. When I put the car in gear (1st) with the brakes on and come up against the converter (around 2200) the motor goes crazy and usually stalls. When I don't hold the brake (on jack stands) It revs normally, but when I lock up the brakes it stalls. I've been trying to tune the lower rpms but no changes seem to make any difference. I hurt the trans last year but didn't think I hurt the converter. The last time out the car left like a stone With the rpms going from 2700 to 3300 up and down for about 100 feet then it cleared up and ran normal. Short time was off by 6 tenths (not a typo). Car made plenty of horsepower and torque on the chassis dyno, So I thought it had something to do with the low end tune. __________________ Art Leong 2095 SS

08-27-2011, 08:32 PM	#5
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,417 Likes: 2,582 Liked 4,453 Times in 1,694 Posts	Re: Symptoms of broken sprague in converter A roller sprag can lock and slip intermittently , but it usually won't do that for long until it quits applying altogether. __________________ We are lucky we don't get as much Government as we pay for..... Will Rogers

08-29-2011, 12:48 PM	#6
Alan Warman Member Join Date: May 2002 Location: San Angelo Tx Posts: 231 Likes: 0 Liked 0 Times in 0 Posts	Re: Symptoms of broken sprague in converter This might be the problem I had all last year. I built a old school TH200 for my car, the front pump uses power guild splines. Had a converter built for it. When I first but it together the converter would brake stall to 3200 and flash to 4800 but it had no high gear. So after talking to several people I bought a Billy Lynn valve body and Billy walked me though the build. Well it had high gear now but the converter would only brake stall to about 2200 and flash to 4200. The car would run dead on times and had 1 to 2 more mph than it should have for the ET that it ran. Does this sound like my problem. __________________ Alan Warman STK 4107