blane17

Took my car for a drive this weekend and noticed some slipping in the transmissionon the highway, when I applied some gas. The engine was rebuilt 4k miles ago, and the transmission was probably rebuilt 20 years ago, if at all. I'm thinking of rebuilding it.... its old, slips, is very tired, and I have trouble shifting into 2nd gear. Anybody have an idea about how much this would cost me? I live in the northeast.

gothand

A three speed manual transmission doesn't slip, however the clutch could. Is it properly adjusted? Where does the pedal disengage it, close to the floor or right at the top? If right at the top, adjust it lower. If it really is slipping, you may have a bad clutch disc and/or pressure plate. I would be pretty surprised if they didn't put a new clutch in when they rebuilt the engine 4000 miles ago, though stranger things have happened.

As for the shifting troubles, it could be the transmission itself or the shifter or shifter linkage. I had a helluva' time with the 1st to 2nd shift in a 4-speedtoploader. If you get the transmission rebuilt, also get the linkage entirely reworked as well. Your car is pretty original so you may not want to swap transmissions, yet that is an option. There is certainly a much larger market for 4-speed toploader transmissions, parts and service.

Good luck!
Jeff

blane17

I'll preface this by saying I know less than zero about transmissions. Whatever I do, I would like to keep the tranny if possible. I'm not a councours or originality freak, but I do like the originality of my car. Having said that, when trying to pass other cars on the highway, there seems to be a slip, or a hhiccup, under heavy accelaration. I assumed this was the tranny, and not the clutch. I will check with the PO and see if he put in a new clutch. The clutch disengages closer to the top, but I will check more closely when this rain lets up sometime this week. What would this have to do with the clutch slipping? Why does it need to be adjusted?

The shift from 1st to 2nd bothers me less than the slipping. If it was just a new clutch/pressure plate, I would be apt to just deal with the tough shifts. How much would this cost relative to a whole rebuild? Thanks for your help

TexasAxMan

What gothand said about the slipping. Don't try to rebuild it yourself unless you have the knowledge and experience. I did and it took me forever just to figure out how to get it apart. I'm no novice at working on cars, but everything has to be in exactly the right spot for you to get everything out of the case. Mine was on a 75 Bronco, but I believe they are the same transmission, at least they seem to be since it looked exactly like the one from my old 65 Stang I had in high school.

I'd try all the adjustments (clutch, shifter linkage) first.

Good luck!

TexasAxMan

You could also have a rear main leak that is causing the clutch to slip.

gothand

Based on your second post, I would eliminate the engine/ignition/fuel out of the equation. Slipping of a clutch will usually show itself under heavier loads like hard launches, steep hills, etc. What you described could be a myriad of things from timing, carb needing rebuilding, valve issues ... In other words, get it a good tune up by a pro who really knows what he is doing before tearing into anything else. As for the transmission, if it is just a bit difficult to shift, I'd rebuild and/or adjust the linkage and shifter and see if it does the trick.

You are in a precarious position. If you are not careful you could **** money into the wind and not solve your issues. Take a huge look before leaping. BTDT.

Good luck!
Jeff

blane17

great. before i do this, i'm gonna back up a step or two and replace my fuel filter & sock and rebuild my carb. I want to rule out any ignition/carb problems. I dont know when my carb was last rebuilt, and its easy and cheap, so i might as well get it done. It will be a good learning opportunity for me and it doesnt sound tough to do at all. I have had weak spark in the past, but i am pretty positive its good now-- i installed a pertronix a while ago and needed to bypass the resistor wire. since then, i have gooten a good blue spark. My car cranks for a bit when starting, so maybe it is the carb. regardless, its cheaper to do than tranny, so ill start there.

Norm Peterson

Going toward WOT in top gear will tend to make a marginal clutch slip even if you aren't going up a hill. It's just that going uphill tends to make you get closer to WOT in normal driving. It's easy enough to diagnose clutch slippage if you have a tachometer - clutch slippage will show up as more rpm's without seeing any speedometer change. If you don't have an in-car tach, you won'tneed to get onejust for this if you've still got access to a dwell tach for setting points. Just run long enough leads to get the meter inside the car and use the high rpm scale.

Ahigh clutch release point can indicate a heavily worn clutch disc. As the disc wears, it gets thinner, and the pressure plate release point has to move further in the "engage" direction before everything comes into firm enough contact to transmit power. Usually, this means less clamping force is available at the PP to prevent the clutch from slipping. And it shows up as a higher pedal ("high" for the pedal being its "further engaged" position). Since the pedal moves more than the pressure plate disc does, a little PP position change shows up as quite a bit more pedal position change.

I'm under the impression that oil on the clutch makes it grabby rather than slip.


Norm

Soaring

Yeah, if your engine takes awhile to start with a pertronix in it, then the carb definitely needs some attention. In the mornings I tap the gas pedal twice then hit the key. I do not even hear the engine turn over before it fires up.

blane17

Looks like I got a carb rebuild ahead of me first. Never done one, but am gonna try. Any good books/videos/instructions out there? Think its an autolite, probably 2100