Transmission Question

[bcjjones]

I just recently bought a used trans on here, installed it only to find out that it grinds in 2nd and 3rd. Seller is being a good guy and standing by his word. He's giving me back half my money.

Question I have is why does the car shift smooth through all gears at idle, at any rpm? It will go into every gear including 2nd and 3rd gear fine at any rpm while sitting still. Can rev it up and down and shift through gears while doing so and never grinds. Only when moving.

I'm assuming that synchros don't really play a role unless the car and axles are in motion?

Also, im not 100 percent sure all the dowels were in when I put the used transmission on. But it shifts fine in all other gears so I think its just the synchros going out!

 

[LOLVTEC]

Just save up and send it to shep. You'll never have to worry about transmission problems.

 

[cola]

Im not quite sure what you're asking so ill give you some info- I mean I cant see inside your trans from Chicago and tell you exactly whats wrong.

If the flywheel is moving and the wheels arent theres still force on the synchros and thats really irrelevant anyways.

If you want to rebuild it yourself read everything this guy wrote DSM Forums - View Profile: turboglenn

 

[bcjjones]

Im sorry, to clarify I guess the only other way to put it is the trans shifts like butter while the car is running sitting still. Not only just at idle, I can rev the engine to any rpm and still shift into 2nd and 3rd.

The trans only grinds 2nd and 3rd while the car is moving. My question is why does it do that?

I mean if at idle while revving the motor, dont the synchros have to work the same in matching the engine speed as they so while driving?

If that makes sense

 

[bryanwheat]

Try adjusting the master cylinder.

 

[bcjjones]

Yea i've played with the master cylinder a little bit. Tried a few different adjustments. Is that not common, I mean shouldn't it always grind not just while moving?

Im still leaning toward the synchros, because also while the car is running and at idle without the clutch pressed in the 2nd and 3rd gear synchros wont hold the shifter out of gear. It'll try to go into and grind as opposed to hold the shifter out of gear like 1st, 4th and 5th gears do. Is that a good test for them?

 

[cola]

Try this

Shifter Adjustment

Im not sure about 1g trannys but I know 2g the gates are at 1/2 3/4 so grinding 2/3 is either an adjustment issue or a worn syncro. Is your slave and master healthy?

 

[bryanwheat]

Im still leaning toward the synchros, because also while the car is running and at idle without the clutch pressed in the 2nd and 3rd gear synchros wont hold the shifter out of gear. It'll try to go into and grind as opposed to hold the shifter out of gear like 1st, 4th and 5th gears do. Is that a good test for them?

That does sound like the syncro's are bad if it just grinds without pushing in the clutch.

 

[bcjjones]

Yea i've done all the adjustments, more then once. I appreciate the links though.

Yea slave and master are brand new. Just gunna have to face the fact that its the synchros. Still dont understand why it only grinds while moving though.

I have a spare tranny, the one i swapped this one out with. Maybe ill try taking that one apart and see how far I get. Maybe I can just fix it myself. Pretty mechanically minded, never done a tranny but rebuilt a few motors including aviation engines.

I apppreciate yalls input!

Edit: @ Bryan...yea thats what I thought. Thanks though

 

[Archer Fabrications]

get it up on jakc stands put it in gear and go through the gears, see if it grinds with no weight on the wheels while they are still able to move.

 

[juntjoo]

Try adjusting the master cylinder.

huh? i'm basically new with transmissions. are you saying that grinding gears could be an issue with the clutch? I've got some serious grinding myself and am planning to do a rebuild but are there other possible causes to grinding gears? btw, all gears grind, 1st the worst, 5th the best. first ten minutes of driving (cold) no grinding.

 

[pauleyman]

OP. No, sitting still is not the same as moving. Lots of tranny internals aren't moving if the car is sitting still. Actually only the input shaft would be moving. Front difff, center diff, and intermediate would all have to be stopped completely. So you have bad synchros, question is what do you want to do about it now and what are you capable of doing yourself?