TR4/4A TR4 Transmission Problem

[SeaAir]

I have a new noise that I think is going to require pulling the transmission in my TR4, but maybe I am missing something. Here are the symptoms:

Not Moving, clutch engaged: a sound like someone hitting the transmission with a small hammer that you can feel in the shifter.

Not Moving, cluch not engaged: no transmission sounds.

Moving, accelerating: no transmission sounds.

Moving, decelerating: same hammering noise, but with a bigger hammer.

Either way, it doesn't sound good. One other question, I've always pulled the engine and transmission as a unit. Is there a way to pull just the transmission on a TR4?

Thanks for the help.

Warren

 

[Banjo]

Your noise is definatly in the tranny. It is probably in the input shaft or on the counter shaft. either a bad bearing or chipped tooth on one of those. tranny internals aren't really my strong point.
as for removing the trans, the answer is yes. It can be removed through the interior. if you pull back the carpeting on the tranny tunnel you will see that it is bolted in. remove a seat, the center dash brace that straddles the tunnel , the carpet, and the tunnel, and the tranny is staring you in the face. It's actually easier than crawling around underneath.
actually once you're that far you can remove the top of the tranny and have a looksee without removing it from the car. You won't be able to do anything about what you see without taking it out, but it'll give you an idea of how bad it is. Hope this helps Guv'na

 

[Alan_Myers]

Hi,

You might try draining the oil from the gearbox, into a clean pan of some sort so you can check it carefully for any metal filings or pieces.

Also check your drive shaft bolts, front and rear.

Internally, I really can't think of what it might be other than what has already been suggested, to cause the symptoms you describe. Perhaps someone else has experienced the same.

Agreed, you can remove the gearbox pretty easily through the interior of the car. You'll need to jack up the engine a bit, raising the rear of the gearbox to get room to move it rearward. Just use a 2x8 2 feet long laying flat on top of a jack, and jack under the engine sump. Be a little careful not to jack it up too far, or the rear of the engine might bend the throttle linkage shaft.

If you have a shop manual, it describes the details of removing the gearbox this way.

And, you'll need to rig something to support the rear of the engine while the gearbox is out, such as a short piece of 2x6 on end, at the rear, propped to the ground. Don't trust a hydraulic jack to hold the weight of the engine while you are working on the gearbox.

I hope it's an easy fix!

Alan

 

[MDCanaday]

If its NOT an OD tranny just locate a replacement box and swap it in, they sell cheap these days in reasonable condition too. If its OD, better build it before it riuns the unit, they go out quickly if there is metal in the oil.....
MD(mad dog)

 

[SeaAir]

Thanks for the replies. I am a little space-challenged in my garage at the moment, otherwise I would have pulled it by now. MD - Where should I look for a replacement? I don't know of anything that is cheap on Triumphs.

W

 

[Geo Hahn]

Always some on eBay, por ejemplo:

https://cgi.ebay.com/ebaymotors/ws/eBayIS...;category=34208

Someone correct me if I'm mistaken here, but I think any post-50000 TR3A thru TR6 gearbox will work for you (though the 3A boxes will have non-synchro first).

A key thing will be if you can find one you can go pick up as the shipping on these may be more than the cost of the unit.