grinding when I put it into reverse.
 

Hi guys,

Can anyone tell me what needs to be done, and about how much it costs to remedy this ugly issue on my 84 930?

Thanks.

If there has been no clutch replacement recently, then the clutch cable probably needs adjustment under the transmission. If the clutch does not release fully, the disk can drag enough to keep the transmission gears turning, particularly when the transmission oil is hot. If you can move the shifter towards first or second to engage the syncros then quickly go for reverse, sometimes you can get it to go in.
If the clutch has been recently replaced it may need more time to seat in to wear the high spots off the disk, but it may still need a cable adjustment to get more release travel.

Hi,
Mine does a similar thing if I go straight into reverse after I have had the clutch engaged while in neutral. I supposed it was because there was no synchro in reverse so now, I depress the clutch, then push it into second (seems to line up the tooth better than first) and then go into reverse. If I don't let go of the clutch pedal in between the two, it's fine... if I engage the clutch and put the shafts back into motion, it will grind again when I put it into reverse. I have no clutch drag otherwise.

There is also the possibility it's as simple as adjusting the shift linkage (in the transmission tunnel below rear seats) if it's a shifter alignment issue.

depressing the pedal methodically 2x can also aid here - but I'd go for the adjustment of the cable / coupler too

Adding to what Paul mentioned above, I find an honest 3 Mississippi count to let the gears settle down before engaging reverse is helpful. If I'm too anxious, I get reminded.

Pretty common on the 930 transmission. I would not stay up late worrying about it.

How long have you owned your 930? If you just bought it then you should follow others advise above (pause for 5 seconds before engaging reverse, etc). But if you owned it for a while and this developed a problem then it could be a number of things relating to shift linkage or clutch.

Winner winner chicken dinner.

I have owned this car since 1989. I did the slant nose conversion on it and painted it myself. I rebuilt the engine and transmission myself. I did the EFI conversion myself. I previously had a Centerforce clutch in since the engine overhaul in 1995. I never had an issue adjusting the clutch or getting it to go into reverse. I wish I would have put the Centerforce back in.

For my latest changes I removed the floor board and adjusted the clutch cable at the front clevis (turned it in as far as it would go), shimmed the clutch pedal stop down (for more travel) and re-adjusted the clutch cable (at the transmission). Note that I had to replace the stock clutch lever adjusting screw for a longer one that would reach the small clutch lever and still have a functional locknut. This the show stopper for me. I can not adjust the cable to provide 1mm (.040) clearance with the adjusting bolt because the car will not go in any gear due to the fact that the clutch is not released fully. I have about .002 clearance on the adjusting bolt. The clutch will release Ok in this state and there is no problems shifting into reverse until the transmission gets good and hot. I have talked to James Patrick at Patrick Motorsports, he maintains that the Kennedy pressure was designed to work with the OEM Sachs disk, which is 10mm thick. So, something is not adding up. It just seems to me the clutch disk needs to be less thick. I don't have many miles on this setup yet, so I am hoping that after the disk seats in this will get better. But even if it gets better, the adjustment is nowhere near stock.

I had a clutch disk (SC) re lined and it turned out 1 mm thicker. Never gave it a thought. But I had a continual clutch problem til I threw the lot out and replaced pressure plate and disc. There was not enough travel in the internals to function properly. The tolerances were quite tight. I had put up with it for a year or two and it never got any better. Only after tearing it down did I find the difference and issue. I'm guessing your extreme adjustments would be due to this.
Alan

why does it matter if the tranny is hot or not?
This is a new problem for me. I took my car in a while back and now it idles at 1100rpm while hot, and I get this issue when trying to go into reverse.When the car is cold, it idles at 9500 and reverse is fine. it;s embarassing to hear the gears grind when I park in reverse, like everyone thinks I'm a moron who had a rich daddy.
My car used to always idle at 9500 and I never had this issue before.
I will say it feels like I need a cable adjustment. Why do I have to do this adjustment every year? is this normal?

my technique is to ease into reverse, wait for the grind noise, put it back into nuetral, into first, try again....still grinds. I wait a little bit between shifts.

thanks

When the car first starts up, the engine oil and transmission oil are cool. Engine oil heats up pretty quickly. Transmission oil the heavy weight oil and is very viscous. As you drive the car it to will get hot, which makes the oil thinner. When the oil is thinner it takes less force to rotate the transmission internals. So if the clutch disk is dragging just slightly with the clutch released it will spin the transmission. When cold the 85-90W gear oil is thick enough to keep the transmission from rotating gears. My car goes into reverse with no problem when cold. But after it gets hot, it will grind. I am hoping when my clutch is broken in, I will be able to get some more clutch cable adjustment to overcome this. If your car has an existing clutch and did not have this problem before, the clutch cable probably requires adjustment. But the clutch cable may have stretched or some other issue with the release mechanism. As the clutch disk wears, that should allow more release travel if you do not readjust the clutch cable adjustment bolt to the 1mm (.040) clearance over time. Perhaps your adjustment is more than .040 clearance.