Technical why does my Muncie 4 speed grind going into reverse?

My avatar. 327/ Muncie 4 speed/ Has new synchros, bearings, seals, and gaskets 40 years ago (really). Now has 140 miles on it (really). Grinds going into reverse. All other gears work fine.

I can get it in reverse if I push the clutch pedal through the floor, but that's a long way from the seat. If the clutch disengages properly for the 4 forward gears, why isn't the same travel enough for reverse. Clutch is a new 11" raised finger diaphragm.

Suggestions?

thx,
.bjb

 

Sounds shifty. Hehe.

 

Reverse has no synchro, forward gears do. Like an old fashioned 3 speed, push in clutch, grab first or second THEN go to reverse. Do not let out the clutch in between. The forward synchro's will stop the spinning then reverse should engage without grinding. Mark

 

What Nosford said.

plus, it sounds like your clutch isn’t completely disengaging. You don’t notice it in the forward gears because the synchronizers mask the fact that it’s slightly dragging.

 

I'll 2nd that your clutch is not fully disengaging...adjust it a little more and see

 

I’ll third clutch adjustment or sear readjust closer to pedal . It’ll be hard on your syncros if you dont readjust .

 

I agree; sounds like a dragging clutch.

 

What nosford said. Been doing it that way for 44 years.

 

Did you lube the spiggot bearing? If not it could be dragging and causing the shaft to spin.
But being a new clutch assy, there will be high spots which need to bed in, take a bit of free play out of the linkage, select a forward gear then reverse for a while, it will be fine..

 

Exactly what I do with my big block top loader, works every time.

 

Spiggot bearing translates to pilot bearing/bushing in lands where you don't stick cutsie names on common automotive parts. Yes the pilot bushing needs to be lubed a bit.

I'd check the free play on the clutch pedal, you want between 3/4 and one inch of free play and any more might not let the clutch release right.

 

I agree with Nosford. I have always put shifter in 1st or 3rd gear... Then put shifter in reverse. Prevents grinding. Trust me, grinding the reverse gear or reverse idler in muncie will cause you nothing but headaches later.

 

Clutch not disengaging. Same thing would happen to mine.

I foolishly put the pressure plate from the car I got the drivetrain from back in mine. I knew better but..........
It was crap. Just replaced it. Slick as butter into reverse.

 

I have always shifted into a forward gear before going to reverse on any manual transmission, to insure that reverse gear didn't scrape or grind.
Muncie, Borg Warner, Saginaw, Ford toploaders, T5, etc. I've just always got into the habit of doing so... since a lot of manual boxes have non synchro reverse gears.

 

How strange! You all agree. That never happens on the HAMB.

Thanks for all the replies. It's been decades since I have driven a stick, so I'll have to be re-trained to go from first to reverse every time. Hope that works.

If it doesn't, I'm in for a re-work. I'm totally out of adjustment on the current linkage setup.

Thanks for the help.

.bjb

 

You may not even have to fully shift into 1st gear. I've had a couple vehicles over the years that I only had to shift "towards" 1st gear, just to the point where you began to feel the shifter detents start to engage. Usually that was enough to stop the counter gear from spinning.

But now I've got to ask a question. Would it be safe to say that no, or nearly no manual transmission ever used a synchronized reverse gear? Maybe some "high-zoot" luxury foreign model?

 

someone put a bag of Fritos in there...couldn't help myself

 

I had a clutch dragging problem on my avatar. I got under the car and had someone work the clutch pedal; what I found was the linkage between the Z bar and clutch fork was not parallel to the centerline of the crank/ transmission main shaft. This caused the fork to twist and the throwout bearing to not apply even pressure to the pressure plate fingers ( diaphragm style). uneven engagement and release is the result.

 

The fork can't " twist " the TO bearing , the throw out bearing is guided by the front bearing retainer .

 

Crazy grinding? Like won't go in grinding? If you can shove the pedal through the floor and it goes in normal, I think you answered your question as long as the throwout bearing isn't riding on the pressure plate, adjust it a little more, until it suits you.

 

The last couple OT 4 speed cars I had you had to shift in to reverse to shut the key off & lock the steering wheel , for 25 years that's what I did it's a habit now.

 

Is the T.O. bearing installed on the fork correctly?

 

If you're under the car and can have someone working the clutch linkage . . .

* Check where the pedal and clutch fork levers connect to the z-arm tube. Look for any flex, distortion, deflection and/or cracks. Look for any signs of rust at the weld joints.

* Look for any flexing of the firewall when cycling the clutch, assuming that the pedal is mounted to the firewall.

You may not be disengaging the clutch as completely as you think.

 

I agree, however, it must have had some effect because the engagement and release was much "cleaner".

 

Fork was binding ...

 

?????

 

Be interesting to see what the reverse idler and the reverse gear look like.

 

Most likely just fine .

 

I have the same problem, thanks all for your opinions.

 

in english, Spiggot is not a word