[Scottsdale]

I have a 90 C1500 extended cab P/U which is not a hot rod by any description. In the past the speedo and tail shaft seal has leaked almost since the truck was new and the trans fluid rots the rubber and causes the transmission mount to fail over time. I am in the process of sealing up the transmission for the second time now. My question is, If I put a Polyurethane transmission mount such as Energy Suspension makes in it, will it increase vibration? Bad idea? Good idea? Pros & cons? I like the Polyurethane because it is resistant to chemicals and trans fluid.

[GSXR1000Dave]

I think the poly is the way to go.Its stronger,but still gives you a bit of flex.I've always upgraded to any poly bushing or mount when I could.As for your rear seal leak,have you had the tail stock bushing and drive-shaft slip yoke checked?If your having to replace the seal often then their is a good chance you got something causing the premature wear.Check the drive-shaft yoke for play while still in the transmission.If their is remove it and check for grooves or wear.If the yoke has either,replace it or polish it depending on wear.Also replace the bushing on the tail stock is their is wear.

[SSedan64]

If the Seal has worn a groove in the Drivshaft Yoke. There is a Speedi-Sleeve to repair this. They're not cheap tho'.