TRS Gimble Bearing?
 

Hey Guys,
I'm a real novice and need help.
I have an old "77" Formula Thinderbird, w/454's and TRS drives. I have lots of questions/problems.
1st is I have a vibration and knocking when i turn sharply. A mech. at the marina said its the Gimble bearing, and he can replace it.
does this sound right, and if so, is it a big deal and how much should i expect it to cost.

thanks for any help
Larry

Do you have B/W Velvet Drive transmissions? The TRS dont have a gimbal bearing, it's in the trans tailstock. Also check the U joints.

Probably U joints.

Sounds like u joints to me aswell.
But if u whant a set of TRS including gimbals and all ,,i have a set for sale.

Thanks you'll,
I felt like it was a u-joint kinda thing,
but i dont know this stuff.
Larry

Dont trs have 2 bearings a gimble and a tail stock because you can get to one by pulling the drive off and the other you have to pull the motor out. I could be wrong but i did mine a couple off years ago because of vibration and the outerbearing was exploded all that was left was the outer race.

Merctrans requires engine removal, the outer bearing on the Velvet Drive transmission can be reached through the bellows - not sure if you can get it out though.

I think I have the Merctrans, ?
Think I'll have them pull the drive, check the U-joints.
Can I then tell if the bearing in the tailpiece is bad or not?
Thanks

I would change both out If I were you. Yea It can be a lot of work but well worth it. I f that bearing was to lock up It can do a lot of damage.

trs u-joints
 

It sounds to me like u-joints.You can check the bearing from outside with the drive off.You can also grease it from outside through the bellows.If you want to change it though you have to pull the engine.

If its a BW 72C, you can change the rear tailstock bearing through the gimble. It sucks, but can be done. Removing the bearing with a slide-hammer puller isn't so bad, its getting the big snap ring off. I don't know how picklejim is greasing his, all the one's I've replaced are sealed units.

As you said earlier you think you have a merc trans,not a borg warner.If the u-joint yoke on the outdrive has a male shaft with external splines it's a BW.If the yoke has a female end with internal splines and a spring on the end it's a merc trans.As for greasing,the aluminum retainer on the end of the output housing has a grease fitting in it at straight up 12 o'clock.You can see this looking in through the bellows. If you remove the retainer ever(which you can only do by removing the engine)be sure to put it back on the same way.There is a hole in the output housing which directs the grease into the bearing.If you need to see a diagram of this go to ishopboating.com.Click on mercruiser diagrams.Then click SHOW MODELS.Scroll down to 330 MIE GM 454 V8 1977-1980 and click on it.Then select transmission assembly sterndrive page 2.This will show you an exploded view of the merc trans.You will see the retainer as part #104.Grease fitting is #108.You must loosen the 6 nuts on the retainer before removing engine.The retainer squeezes the rubber mount #103 tight in the transom housing to serve as your rear mount.