[[email protected]]

Issue with my 65 El Camino is really frustrating. I recently installed a fresh built L79 engine. Flywheel was resurfaced by machine shop and new clutch assembly was balanced by the same machine shop. Also fresh rebuilt 65 M20 transmission. rebuild of trans included a rebuilt kit, new hub assemblies, sliders and synchronizers from D&L Transmission.

I have a stock Muncie shifter on the transmission.

I have adjusted the clutch to specs from the service manual. I made a shifter neutral gate tool/gauge that fits the shifter neutral gate nice and tight and have checked and/or adjusted the rods more that a couple of time.

Now to my issue. When I first start out for a drive, everything is fine. Shifting through all the gears is fine; however, after driving for 20 to 30 minutes and everything is warmed up, shifting from 3/4 down to 2nd or 1st is very difficult. Coming up to a light and down shifting from 4th to 3rd, no problem, then trying to go from 3rd to 2nd many times is near impossible. It is not an issue of gears grinding, just will not go into gear. Most of the time I can finally get it into gear by going back up and down. Also, if I pull into a parking lot and attempt to back up, several times reverse really grinds, even if I am able to go back into 2nd then try reverse again, a lot of grinding.

On two occasions, The transmission has actually gotten stuck in a gear. I stopped to get gas and put the car into reverse will filling up. When I restarted the car and shifted out of reverse I must have gone into 2nd gear. I could not get it out of 2nd and drove 25 miles home in 2nd. I put the car up on my lift and using a set of channel locks I flipped the shifter lever on the transmission 2/3 fork back to neutral. No resistance at all, it just easily when back to neutral.

Yesterday I was out for a drive and stopped at a local Home Depot to pick something up. I pulled into the parking lot and was having the normal issue of down shifting to 2/3, some how the transmission got stuck in 4th gear. No matter what I did with the shifter handle I could not get it out of 4th. Engine running or not, made no difference.

So I when into the Home Depot, bought a channel lock, crawled under the car and popped the shift lever back into neutral. No effort at all, just when right into neutral. No further problem driving home.

Some of what I have done is I spoke to Larry at D&L Transmission to see if he though I could have screwed anything up doing the transmission rebuild, and his opinion is no.

I have adjusted the clutch fork to beyond the service manual spec and now have it very close to the through out bearing. My thinking was maybe the clutch was not fully disengaging.

I certainly would appreciate any comments if someone has had any similar issue and managed to figure out what is wrong.

Thanks,
Don

 

[71350SS]

I hope someone with OE Muncie shifter adjustment experience can help you with this as all the Chevelle's I had and my ElCamino had replacement Hurst shifters by the time I got to own them.
As for the downshifting problem that can be internal and it's something I learned over the years not to use to slow the car down.Its much less wear and tear on the clutch and the trans to just let the brakes slow the car down and only down shift to match the gear to the speed of the car after slowing the car down.

 

[DUTCH MAX HEADWORK]

You're not getting a full clutch release you're having a hard time shifting because the input shaft is still connected to the transmission and spinning with the transmission instead of releasing. That's the same reason you can't shift into reverse you're versus unsynchronized so you're trying to put it in reverse but Dad diaphragm clutch everything input shaft still all spinning together.

 

[jmartorana]

IMO you can rule the clutch adjustment out of this problem. It could be as simple as a loose bolt or nut on the transmission 1-2 or 3-4 shift fork, or you simply need to rebuild the shifter (worn bushings) or better yet replace it with a Hurst Competition Plus and dont look back.

 

[DUTCH MAX HEADWORK]

Sorry text to speech. And a little bit of spell-checker kicked in there.

It may not be clutch adjustment. It could be your pilot bearings too tight, your bellhousing alignment is off. Or for whatever other reason your clutch is not fully disengaging in the input shaft keeps turning that's why you can't get your 3-4 shift that's why I grinds going into reverse. And if it is a clutch it's because you don't have enough free play and your clutch Fork angle is off.

 

[blm]

When you went to install your rebuilt trans did it slide right in or did you have to use a little force to get it fully seated against the bell housing?
I’m not thinking it’s worn bushings, etc. as I believe you are saying it’s a new problem. If it were a worn problem you would have had same issue before you rebuilt trans.

 

[robertr63]

Just a guess but if the channel locks move the linkage that easy and the shifter won't , maybe it is the shifter.

 

[Wingwrench]

The shaft that goes through the shifter and holds it all together is probably worn out along with the arms in the shifter. I had a similar problem in a friend's 68 Vette. Maybe similar to these.

https://i1.wp.com/www.chicagocorvette.net/images/diagrams/large/B-SHIFTER-02-shifter-components.gif

 

[[email protected]]

So a little more info:

I actually have two OEM Muncie shifter (only one set of rods) and I have the issue with both of them. I find it hard to believe that both are bad, but I guess anything is possible.

I have adjusted the clutch to the point the throw out bearing is almost riding on the pressure plate fingers, so if I'm not getting full disengagement then something must be wrong with the linkage. I have the correct OEM parts, bellhousing, clutch fork, fork ball in the bellhousing, bell crank, pedal push rod and lower push rod. I will see if I can get any more adjustment on the clutch.

I installed a new pilot bushing when I installed the transmission to the engine. I checked fitment of the pilot bushing to the input shaft tip and that was fine. Also, when I installed the transmission, it when right into the bellhousing, clutch assemble and pilot bushing. No issue at all. The one thing I don't remember checking is whether the pilot bushing was Oilite?

I really wanted to keep everything near OEM. But I have a Hurst shifter that will probably be my next step. I do not have the correct Hurst installation kit, so I guess I'll bit the bullet and send $200 to buy the kit.

If that doesn't fix my issue, next step is to pull the transmission and check clutch assembly and replace the pilot bushing after I make sure I have a Oilite bushing.

Thanks again,

Don

 

[DUTCH MAX HEADWORK]

This is actually a common problem happens a lot.

Jack up the back of your car and put your car in gear well your foot on the clutch if the back tires are still spinning your input shaft is spinning your clutch is not disengaging or something is keeping your input shaft connected to the flywheel

. I'm working right now but post something up for you little bit laters

 

[[email protected]]

This is actually a common problem happens a lot.

Jack up the back of your car and put your car in gear well your foot on the clutch if the back tires are still spinning your input shaft is spinning your clutch is not disengaging or something is keeping your input shaft connected to the flywheel

. I'm working right now but post something up for you little bit laters

Great suggestion. I've never heard that. I'll try it tomorrow morning.

Thanks

 

[Wingwrench]

At least disassemble one of those shifters and see what it looks like before pulling the trigger on the Hurst shifter. They are good, but you may find that their are worn parts. But your call

 

[DUTCH MAX HEADWORK]

Sounds like that shifter is giving you fits. I'd get that under control by rebuilding it or just flat replacing it with the Hurst. I have some rebuild instructions HERE> 1964-1981 Corvette 4-Speed Shifter Rebuild. Zip's Corvette has rebuild kits, last I heard they were still in business.

Another test you can do to determine if you are getting a full clutch release is the 9-second test. Start with the engine running and the clutch released (pedal up). Apply the pedal fully and attempt to shift into reverse. You should be able to shift into reverse within 9 seconds without grinding. If she grinds or continues to grind, your input shaft is still rotating due to a mechanical fault in the system. You can cheat this for a little while by shifting into first gear then reverse. But you will eventually destroy your 1st gear Syncro and your 3-4 Syncro will also get beat since it has to speed or slow the assembly before the gears will mesh and it will be fighting the input power from the input shaft.

You said you checked the pilot bushing, was that after it was installed because they tend to shrink down after installation into the flywheel. The input shaft of a new Muncie trans is .590 and you need about .003 clearance, so .593 installed diameter on the pilot bushing.

If your engine was line bored, then I can guarantee your bellhousing alignment is out of spec. All installations should start with a parallel and then concentric alignment of the bell housing. If you like gambling and bench pressing transmissions, you can skip this step.

Since all clutch parts and flywheels can be out of stock spec, you really need to and set your clutch fork angle. More than likely, you will need an adjustable pivot ball or adjustable throwout bearing to compensate for manufacturing inaccuracies or neglect. Resurfacing a flywheel can throw you out of spec.

Grab some pictures of your clutch fork angle and we'll take a look at it. Slide your phone against the frame rail and shoot away.


Correct 5-7 degree forward clutch fork

If you have this clutch fork with "wings" You have the incorrect clutch fork and you're losing throw due to the extended length of this fork.

It was difficult to verify the angle on these shots, but this ended up working. One of many customers from this site.

The above describes the clutch fork angle/eyeball method.

This video shows the measurement method and use of an adjustable pivot ball. I suggest using this method to set and the 5-7 degree forward angle then use it to calibrate your eyeball, then use a stock pivot ball and a McCleod adjustable throwout bearing and duplicate the forward angle unless you are using a Centerforce clutch, then you need to use a Novac bearing or the pivot ball. If you use an adjustable pivot ball, insure you have at least the with of the bolt worth of threads left in the threads and REDLOCTITE once you get it set.

 

[blm]

One should measure the outside diameter of the pilot bushing (with dial calipers) and the inside of the crank bore ( with a T gauge) to make sure the pilot bushing is only 2-3 thousandths larger than the crank bore. I’ve seen them as much as 7 thousandths larger. If one installs a bushing that oversized it will compress and the input shaft will get hung up in the pilot bushing.

 

[[email protected]]

Dutch, thanks very much for all the information. All very helpful.

The first thing I want to do is your test to see if the input shaft is still turning. However, I need to take the car out for a decent drive to get everything warmed up. When it is first started cold/cool, I have no trouble shifting into any gear, including reverse.

It is pouring rain here today, so this may be a weekend project.

Will the Corvette shifter parts fit the Chevelle shifter? There are differences in the shifters. For one, the shift lever on the Corvette shifter is part of the shifter and on the Chevelle the lever bolts onto the shifter. Do you know if the internals, i.e. levers, etc. will fit?

I have the correct clutch fork, picture attached is of a spare. This is the kind I have installed now.

 

[chaze]

Since both of your OEM shifters have the same problem I suspect that the internal sliders are worn beyond adjustment remedies.
I had the exact same symptoms as you with a 66 Muncie shifter. I dismantled it and attempted to adjust / repair it but the slider on the bottom of the shift lever (part # 6 in Dutch's pic) would frequently allow the 1-2 lever (#16) and the reverse lever (#14) to engage simultaneously which locked up the transmission.

Another wear item is the reverse lockout pin on the side of the shifter body (not shown in the pic) which can allow both the 1-2 lever (#16) and the reverse lever (#14) to engage simultaneously and lock up the transmission.

I was very lucky to find a less worn muncie shifter from a friend that works flawlessly.

 

[71350SS]

I don't think a Corvette clutch fork will work with a Chevelle clutch linkage.Someone on TC recently had to replace one of them to fix part of his problem.From what I remember it put the adjuster rod at the wrong angle.
But with the shifter parts IDK if they will interchange with Chevelle parts ???

 

[Lew540]

Also check your Z Bar thing make sure its not flexing, loose or about to break. I had this happen in a parking lot. Same kind of thing got worse and worse shifting then broke. The Corvette ones were reinforced.

 

[buzzbomb2]

Issue with my 65 El Camino is really frustrating. I recently installed a fresh built L79 engine. Flywheel was resurfaced by machine shop and new clutch assembly was balanced by the same machine shop. Also fresh rebuilt 65 M20 transmission. rebuild of trans included a rebuilt kit, new hub assemblies, sliders and synchronizers from D&L Transmission.

I have a stock Muncie shifter on the transmission.

I have adjusted the clutch to specs from the service manual. I made a shifter neutral gate tool/gauge that fits the shifter neutral gate nice and tight and have checked and/or adjusted the rods more that a couple of time.

Now to my issue. When I first start out for a drive, everything is fine. Shifting through all the gears is fine; however, after driving for 20 to 30 minutes and everything is warmed up, shifting from 3/4 down to 2nd or 1st is very difficult. Coming up to a light and down shifting from 4th to 3rd, no problem, then trying to go from 3rd to 2nd many times is near impossible. It is not an issue of gears grinding, just will not go into gear. Most of the time I can finally get it into gear by going back up and down. Also, if I pull into a parking lot and attempt to back up, several times reverse really grinds, even if I am able to go back into 2nd then try reverse again, a lot of grinding.

On two occasions, The transmission has actually gotten stuck in a gear. I stopped to get gas and put the car into reverse will filling up. When I restarted the car and shifted out of reverse I must have gone into 2nd gear. I could not get it out of 2nd and drove 25 miles home in 2nd. I put the car up on my lift and using a set of channel locks I flipped the shifter lever on the transmission 2/3 fork back to neutral. No resistance at all, it just easily when back to neutral.

Yesterday I was out for a drive and stopped at a local Home Depot to pick something up. I pulled into the parking lot and was having the normal issue of down shifting to 2/3, some how the transmission got stuck in 4th gear. No matter what I did with the shifter handle I could not get it out of 4th. Engine running or not, made no difference.

So I when into the Home Depot, bought a channel lock, crawled under the car and popped the shift lever back into neutral. No effort at all, just when right into neutral. No further problem driving home.

Some of what I have done is I spoke to Larry at D&L Transmission to see if he though I could have screwed anything up doing the transmission rebuild, and his opinion is no.

I have adjusted the clutch fork to beyond the service manual spec and now have it very close to the through out bearing. My thinking was maybe the clutch was not fully disengaging.

I certainly would appreciate any comments if someone has had any similar issue and managed to figure out what is wrong.

Thanks,
Don

Sounds like your bushings in the shifter need replaced. You also need to pull shifter and check for excessive wear as when bushings go bad and the shifter is dirty or worn binding occurs and they will lock in gear and do all kinds of crazy things.

 

[[email protected]]

Sounds like your bushings in the shifter need replaced. You also need to pull shifter and check for excessive wear as when bushings go bad and the shifter is dirty or worn binding occurs and they will lock in gear and do all kinds of crazy things.

I’m pretty sure I have eliminated a shifter issue. I’ve tried two different Muncie shifters and now have a Hurst shifter installed. Non solved my problem.