4R75 build
CVN member lost 3rd and 4th on the transmission in his 2005 CVPI. He pulled transmission and brought to me for a rebuild.
First thing that I noticed, the front pump seal had been "glued" in place with RTV/silicone. During tear down I found all of the front pump to case bolts were loose, 2 were finger tight. Basically, the transmission had been rebuilt previously and they did a crappy job. The direct clutches were worn and there was excessive clearance, the OD band was glazed and starting to burn. The intermediate clutches were glazed and the steel plates were severely hot spotted. The previous rebuilder used the old style, scarf cut sealing rings on on the output shaft that seal the direct clutch. These seals are sufficient for a short time, when they are new, but as they get hot they collapse, don't seal well anymore and you loose pressure to the direct clutch. The one piece teflon seals work much better and don't collapse over time.
The direct clutches were severely worn/deteriorated. These clutches appear to have been some off brand, aftermarket clutches, that I had never seen before. They had an unusual horizontal pattern, where most OEM/raysbestos/borgwarner clutches have a vertical pattern.
The direct steel plates also had an unusual wear pattern, which I had not seen before.
The intermediate clutches were glazed and the steel plates were hot spotted. It's difficult to see in the pictures I took, but they were regular tan paper clutches that have been discolored,
I believe these were Alto red clutches. The problem with smooth clutches is they hydroplane on the fluid and will glaze quickly. The factory clutches are made of carbon material and have grooves to displace the fluid and eliminate the hydroplaning.
A full rebuild was done;
New rubber seals, gaskets, O-rings and Teflon seals.
New Raysbestos clutches, correct material and proper waffling for fluid displacement which prevents glazing.
Lubrication improvements to Direct drum and front stator support. This allows better fluid flow to critical areas for better lubrication and cooling.
New Overdrive band. Updated band with High carbon material that resists wear. Installed Sonnax Overdrive servo pin with o-rings for better sealing - http://www.sonnax.com/parts/2379
Rebuild Valve body with Sonnax replacement valves and performed Jmod
First thing that I noticed, the front pump seal had been "glued" in place with RTV/silicone. During tear down I found all of the front pump to case bolts were loose, 2 were finger tight. Basically, the transmission had been rebuilt previously and they did a crappy job. The direct clutches were worn and there was excessive clearance, the OD band was glazed and starting to burn. The intermediate clutches were glazed and the steel plates were severely hot spotted. The previous rebuilder used the old style, scarf cut sealing rings on on the output shaft that seal the direct clutch. These seals are sufficient for a short time, when they are new, but as they get hot they collapse, don't seal well anymore and you loose pressure to the direct clutch. The one piece teflon seals work much better and don't collapse over time.
The direct clutches were severely worn/deteriorated. These clutches appear to have been some off brand, aftermarket clutches, that I had never seen before. They had an unusual horizontal pattern, where most OEM/raysbestos/borgwarner clutches have a vertical pattern.
The direct steel plates also had an unusual wear pattern, which I had not seen before.
The intermediate clutches were glazed and the steel plates were hot spotted. It's difficult to see in the pictures I took, but they were regular tan paper clutches that have been discolored,
I believe these were Alto red clutches. The problem with smooth clutches is they hydroplane on the fluid and will glaze quickly. The factory clutches are made of carbon material and have grooves to displace the fluid and eliminate the hydroplaning.
A full rebuild was done;
New rubber seals, gaskets, O-rings and Teflon seals.
New Raysbestos clutches, correct material and proper waffling for fluid displacement which prevents glazing.
Lubrication improvements to Direct drum and front stator support. This allows better fluid flow to critical areas for better lubrication and cooling.
New Overdrive band. Updated band with High carbon material that resists wear. Installed Sonnax Overdrive servo pin with o-rings for better sealing - http://www.sonnax.com/parts/2379
Rebuild Valve body with Sonnax replacement valves and performed Jmod
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