Checking transmission health with bad clutch

First, you start with telling us whether it is a 6-speed manual gated box, or an F1 shifter box.

 

Gonna need a bit more info like Yelcab said. Is it completely undriveable? What makes you concerned the transmission may be damaged?

 

IIRC you should be able to cycle through the gears with your foot on the brake. However, I feel I should mention that if it's being sold needing a clutch, it's a good possibility it needs other things too.

 

A 360 clutch job is $4,000. Then if it is 1999-2002 model, you will need to replace the TCU with one that can talk to a non-factory SDx computer in order to set up the new clutch. That upgrade is $2,000. Testing the health of a gearbox with a worn out clutch yields inconclusive results. For example, is it not shifting well because of the synchros or because of the clutch? Besides, you can feel the shifting action with a manual shifter in your hand. There is no such feel with an F1 box.

A heat exchanger failure that is not fixed will cause differential noise issues. You won't feel it in the shifting. At the present time, the fix is to replace the whole transmission because the ring/pinion is no longer available new.

For the car you are looking at, just lob $5,000 off the price if you are serious. That is enough for a clutch and ... gets you 2/3 of the way there for a used 360 F1 gearbox. The rest of the way is you taking on some risks.

 

Failed heat exchanger does not kill syncros, it kills the ring and pinion. Toss the gearbox.
A worn out clutch does not keep a worn out syncro from grinding or a bad ring and pinion from howling.

 

Disagree 100%