shortwing

Friend has an 85 22rec that grinds whenever you try to get reverse. Gears 1 - 5 work just fine but reverse grinds very bad. The clutch was bled and the slave cylinder moves about 1/2 inch when the pedal is pressed to the floor.

It only grinds in reverse, forward gears are ok. The truck sits a lot and he only drives it every few months to tow his boat. He has been turning off the engine, putting it in reverse and restarting the engine.

Zinek

I don't think that the reverse gear has a syncro on it , so its normal for it to grind a LITTLE BIT (check trans fluid level, and viscosity) . What I usually do is before I shift in reverse, I put it in first , cause it has a sycro and slows down the trans cogs and then I put it in reverse without any griding.

shortwing

Trans is full and the right vis.
I tried the first then into reverse. It grinds so much you can't get it into reverse gear. First is ok, ie no grinding

83

Remind me what REC is?
Is the idle really high?

shortwing

22 REC is the california version of the 22RE
I don't recall the idle RPM. However this is an older gentelman who has his own ideas about setting the timing and idle speed ( I'm being political correct). I will check that next it could be high and I didn't notice.

83

Well, I just know that when my carbed truck is on high idle speed (cold), reverse will grind a lot worse. Probably not what's going on here, I think you'd notice if it was high enough to cause this, but it was worth checking. Reverse really shouldn't ever go out. Other gears should first if there's a tranny problem, but who knows.

86tuning

Sounds like a sticky clutch that isn't releasing properly. If the hydraulics are fine, you'll need to tear it down.

Try removing the clutch fork boot and see if the fork hits the edge of the housing when you step on the clutch. If it does, then your clutch is worn out and needs replacement.

shortwing

That's a good sugestion. I will check it. There is no leak down on the clutch cylinder. We held the clutch pedal down for a couple of minutes with a ruller measuring the arm and the travel stayed the same. Sounds like a sticky clutch or a bad pilot bearing. Truck has 130,000 miles on the original clutch.
Thanks for the help.

83

I'm not sure what the pilot bearing would have to do with it.
Hopefully somebody will educate me here, but why would a bad clutch only show up with reverse? Because it's not synchronized? Or just one of those things where sometimes issues present themselves in ways that don't really make sense, but they are the issue all the same?

I've just only had slipping clutch issues, and worn out clutch only engaging when the pedal is all the way up off the floor, but never an issue with it grinding when trying to shift, especially only in one gear.

83

Also, whenever anybody's got a transmission-related problem, I like to direct them to the Marlin Crawler forum. There's a bigger concentration of tranny-specific knowledge over there.

86tuning

A seized/rusted up pilot bearing can be the cause of a sticky clutch. Release bearing is not as likely to fail in this manner. It's much bigger, and tends to create squealing noises as the fingers of the clutch cover (or pressure plate) slip on the face of the bearing.

The main issue is that the clutch is not releasing. 9/10 of the times it is due to faulty linkage. On our trucks, this means hydraulics or pedal bracket failure (which usually squeaks). The remaining 1/10 of the time it's due to clutch failure.

The reason why it's not felt in the forward gears is because the synchronizers mask the sticky clutch. A sticky clutch, as described, will wear the crap out of 1st gear synchro very quickly. I'm sure the driver has simply gotten used to the feeling of a sticky clutch in the forward gears.

There's a saying that goes something like this:
90% transmission problems are clutch problems.
90% of clutch problems are linkage problems.

shortwing

This is what I was thinking - I like to have a good idea what the problem is before I take something apart.

Steve

86tuning

I briefly mentioned it, but take a GOOD look at your clutch pedal and the bracket that holds it. Sometimes they crack, and you don't get full pedal travel, which could definately cause these symptoms.

Cheers.