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TR4/4A TR4 Transmission Cover: The Three Big


Luke Skywalker
Country flag
Moss and VB refer to their replacement Transmission Cover as being Fiberglass but TRF says space-age plastic.

Also, I see that VB sells a bolt and plate kit for installation of the Cover, and it looks quite handy.

Any thoughts between the three.


Several of my bolt holes on my current one are cracked out, though I'm tempted to "weld" some wood or cardboard using fiberglass resin and nylon mesh.


Jedi Trainee
I bought the polyethylene transmission cover from Moss as well as the sealing kit and bolt hardware and was pretty happy with it. Was a bit fiddly getting the holes in the right place on the new cover as they do not come pre-drilled but was not too bad.

Don't usually get stuff from VB, but I don't see on Moss where it says the transmission cover is fiberglass. Think the original ones were fiberboard so the polyethylene is a step up in durability IMO.

Perhaps you are thinking of the drive-shaft tunnel cover, I believe they offer both fiberglass and fiberboard covers on Moss. I can't speak to either of those though.

Geo Hahn

Country flag
KVH - for what it's worth, local TR owner Craig S has used both and mentioned to me that he thought the poly cover was a more difficult fit, the fibreglass version fit quite well.


Darth Vader
yes but they both are still a pain especially if you have an OD unit the angle spedo drive interferes with the cover, you either have to cut a hole out and make a cover or do as I did and heat the poly and expand it with a hammer handle and that worked quite well also on the poly I made elongated holes so I didnt have to pry it into place


Marvin Gruber

Country flag
See, I've had more luck with the poly, I could move it around more. Poly doesn't seem to crack or tear like the fiberglass. Either is better than the cardboard.



Jedi Knight
Country flag
If it's just those bolt holes and the rest of the cover is sound, then repair it using resin and fiberglass mat. I made some major repairs to mine(someone had cut it to get it around the shifter for removal). I covered the underside with reflectix insulation and once the rug was over it no one will ever know it was repaired.


Jedi Trainee
I bought the poly one and install kit from BPNW. I don't recall any fitment issues with it in my 250 with OD.
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