Need help with drivetrain diagnosis

[T4WDOR]

So i bought an 86 sr5 that i was going to use as a parts car, but the engine runs so good that i feel like i have to fix it. The car is undriveable right now(due to the grinding).
So when i start it there is no grinding, and the car will go into any gear easily. But when i let the clutch out in gear or in neutral it grinds horribly bad, it will move(which is how i got it into my backyard), and when i moved it i could feel whatever was grinding take the power away from the car.
I am no mechanic, but it seems to me like if it were the transmission i wouldnt be able to shift into gears, and i would still be able to let the clutch out in neutral. I did my share of internet investigation and have heard people talk of throwout bearing and clutch problems.
The kid i bought it from claims a couple of mechanics listened to the grinding and claims its the transmission, but im not convinced.
If anyone would help me with my diagnosis i would really appreciate it, thanks a bunch.

[takza]

With most transmissions this noise would indicate bad main shaft bearings...on the T4WD...it might also be the input shaft bearing. Probably is in the trans and it probably doesn't look too good in there. You could drain the trans oil and look for metal fines in the oil.

Once metal has circulated thru the trans...you can replace parts...but a lot of damage has been done....though the differential in mine went 20K or so after running in metal soup when a bearing failed on a trip (trans changed out).

[dlb]

like takza said, drain the trans oil and check if it's full of metal flakes and filings. if so, the trans is toast. if not, and if you're able to remove the engine, i would do so and then inspect the clutch and input shaft bearings. it's a fairly big job but if you have an engine hoist and concrete slab it's not so bad. if you can be positive which bearing it is, there are ways to remove/replace them without removing the engine and trans.

this is actually a good video about clutches, how they work, and some common problems one might encounter with them. pretty relevant here. it's 15 minutes but worth a watch. he describes some problems that sound similar to yours so it might be useful.

http://www.spike.com/video-clips/muh1k8 ... lutch-work

[T4WDOR]

thanks a ton thats very helpful, ill have to drain the oil and see what i can find.

[Petros]

That could be the clutch, or as noted the input shaft bearing (an easy replacement once the trans is out), also the throw out bearing and pilot bearing (also easy replacement once the trans out). The trans has to come out to fix the clutch anyway. pull it and see what the clutch looks like.

You have to drain the trans gear oil before you pull the trans, so drain it into a clean container and examine it. Note that fine metal flakes are not unusual from a worn but working trans, large metal flakes or partials means the trans is done.

Either way the trans has to come out, once out inspect the clutch for damage. If you get that much grinding it should be obvious if it is the source of the noise. Also once the trans is out you can turn the input shaft by hand and feel for any grinding in the trans.

[arbskynxnex]

When you drain the oil pull the fill plugs first, sometimes they can get stuck and if you've drained your oil and can't refill it you are out of luck.

If it is your clutch, my preference would be to pull the engine instead of the transmission. The tranny is a bear to put back in, plus you'll have fewer components to remove.