Reverse Occasional Grinding Question

[orangetwist]

Ok guys heres the issue. Every once in a while my tranny grinds going into reverse. The only way i can get it to go in is to go back into gear move a little, then go into R.

Now this doesnt do it all the time. It almost always does it if ive been driving forward and then go to back into a space, like at a show or back into my driveway. It seems like the gears are still spinning at a constant speed. If ive been parked, I can start it and go from 1st right to R no problems.

This part sounds weird, but it seems like (for example), say i leave my house to go to a show. If i get on it, not real hard just a good run through the gears, during that drive, it will be more likely to grind when i try to back into a spot at the show.

-Ive adjusted the rods, no change.
-Adjusted the clutch, no change.
-Fluid change, no difference.

Heres my process of normally going into R. Stop, go from 1st to N for a sec, then go to R. Sometimes it goes with no problem, other times it grinds.

Heres what ive noted about when it does it.
-I can stop, go out of 1st to N, wait for a sec then -go to R. Still grinds.
-I can stop go directly from 1st to R, still does it.
-I can stop go from 1st to any other gear back to N for a few then try R, still does it.
-I can stop, go from 1st to N, let clutch out for a sec, clutch back in, then try R and still does it.

Specs: 71 duster, 360, Brewers built 4spd (P.O. Installed) less then 3k miles on it, hays clutch, hurst comp shifter with pistol grip. Previously had hursts short shifter, the one thats like 12" long if that, and i cant remember if it ever did it with that shifter or if it just started after the Pistol grip install. But I dont see why a diff shift handle would make a diff.

Whats everyones opinions? I tried to put as much info as i could think of and everything I have tried while experimenting with it. I really want to figure this out. Its more embarrasing than anything when it does it. Makes it look like I cant drive a manual.

 

[67Dart273]

If the trans shifts easily between forward gears, the solution is to NOT leave it in neutral for "a few seconds." I never did, "back in the day."

I used to be usually in 1st or 2nd from "what I was doing", and was in the habit of stopping the car, LEAVE it in forward gear, and then when I was stopped, and ready for reverse, I'd just shift directly from 1 or 2 to reverse.

If for some reason I DID get into neutral, instead of trying to grind into R, I would FIRST put the box back into 2nd, and then go directly from there to reverse.

A slightly dragging pilot bushing can cause this, as can minor bellhousing alignment, AND clutch dragging slightly.

My old 70 sixpack car had the **** 10 7/8 so called compact 11" clutch cover. I continually had problems with that---the disk would get "fuzzed up" on the outer edge and would drag on the mounting bosses of the cover, which were VERY close to the disk on that setup.

(In later days, running the 340 in that car, I used a late 70's hi perf. 'Vette 10 1/2" diaphragm cover.)

 

[orangetwist]

ok. i see what you are saying...now that you say that, and got me thinking about it, for some reason whenever im stopping to back up i always pull it out of gear before im completely stopped. i think its a habit from the rollback i drive.

 

[wirenut]

Make sure the clutch is properly adjusted so it is disengaging and put it into a forward gear to slow down the internals before putting it in reverse

 

[Purple Haze]

I just go from 1st to reverse, if it won't go in just put in neutral then 1st and reverse again. It's just the gear teeth butting, just got to get them in position to mesh, but if you don't use first it will grind. Using first before reverse stops the gears from spinning.

 

[LovetheA's]

Orangetwist

I don't now if this would be helpful but I had some major problems with my 4 speed tranny last year and it was all due to something very simple. I would have to actually shut my car off to get it to go into reverse smoothly or it would grind very bad. The reason being the pilot bushing at the end of the input shaft on the tranny wasn't machined strait and correct. It would hang up on the input shaft ever so slightly and keep it spinning so when I went to shift into reverse bad grinding. A major problem that was 10 dollars to fix.

Carl