Transmission

I am changing the engine in my 79B to a newly rebuilt 1950cc one with crossflow head, cam, etc. I wonder if I should rebuild the transmission, clutch & overdrive while I have the car apart. Everything seems okay except it slips out of 3rd gear every now & then when power is not being applied (zero throttle), but I want everything in top-notch condition. Do any of you do that? I could ship it I guess. I would like to have the car back in operation as soon as possible. I am in Jackson, MS. I am really enjoying reading you guys stuff on this forum even though I don't know enough to contribute. Down here we'd call ya'll "good ole boys".

Sounds like a 3rd gear synchro. I don't do trannies, but used ones are cheap.
Some of us call ourselves "good ole boys".

As long as you have the engine out of the car, it would be false economy to not replace the clutch, pressure plate, throwout bearing, etc. After spending a couple of thousand or more for the engine, why not spend a hundred or so for a new clutch? If you have to pull the engine in six months to replace the clutch, you will kick yourself.

Check the clutch slave cylinder carefully. If it isn't perfect, rebuild or replace it.

In any case, replace the clutch hose. It's cheap and this would be the perfect time to replace it. Also, do the little rubber boot that fits over the clutch lever and keeps the dust out.

The slipping out of 3rd at no throtle must be a comon thing for 79B's. Mine's been doing it for a long time, and doesn't seem to have any other problems. If that's all that's wrong, if it was me, I wouldn't worry about it. The rest of the advice about clutch, etc. is right on.

You do need to worry about it. You are loosing 3rd gear syncronizer. The next phase will be scraping when you down shift. Then when you up shift. Sounds like you might have a little surplus HP built into that 4 banger. You need to consider getting a rebuilt tranny from VB or one of the other suppliers. I do rebuild trannies,but more times than not it's cheaper to get a rebuild. Don't think once I chack the case on your tranny all I will have to do is replace the syncroes. There WILL be other problems lerking in dark places. If you want me to look at it,I'm in Memphis right at your back door. I also have some used trannies,but considering what you have put into the engine,I wouldn't start cutting corners at this stare of the game. I bumped my Midget from 65HP to 130 and in the first six months I broke two trannies and rung of two rear axels. I don't do 2nd gear fish tails any more. It sure is fun playing with those Jap cars and these so called hot rod pickumup trucks with their glass packs and all.

My 77B grinds in every gear when I down shift. I end up double clutching and blipping the throttle to get a decent down shift unless I am going slow. I was hoping it was the clutch. Not so?

Since it is every gear, clutch is a good bet. How are your hydraulics?

It's a real long shot that you have 4 bad syncroes. It's one thing for sure if it is your clutch hydroes you really need to deal with it. It could be something as symply as replaceing your hose. If the rubber is breaking down inside the hose it will restrick the flow and slow the clutch action down. If you don't deal with it it can get REAL expensive. Take a pair of dikes and snip a small hole in the boot of the clutch slave. If any,and I do mean any fluid comes out or if it's wet at all inside the boot. At the very least you need to put a kit in it. Don't forget to hone it out. Check the back of you clutch pedal. If there is any sign of wetness you have a bad master cyl. Then again it may be that all you need to do is suck out the old fluid and flush the system. That's almost as long a shot as 4 bad syncroes though.

Fluid level is good,no cylinder leaks, although I haven't tried to bleed the system yet. The vehicle was not driven much in the past 5 years and when I bought it in August, it didn't upshift very well either. adding oil (20/50) to the trans. and driving it, seemed to pretty well take care if that problem although you can't shift quickly even now. My rear main seal leaks but the clutch doesn't slip or shudder yet.

You may have a bad clutch hose

As Tom has said before, "It's hard to diagnose from 3000 miles".
No slips or shudders, probably not your clutch hard parts.
Try the flush and new hose like Tom said. What bothers me is the new info about being hard to shift up until you put oil in the trans.
How much oil and did you drain the old first?
Clutches don't get better because you put oil in the gearbox.

I didn't drain the old oil out, (probably should have).I had the car on ramps with front end up, so I put in about a quart,forgeting that is was not level ,I pushed it off the ramps to level it out and let the excess drain out ,so I think I actually put in about 1/2 quart.It definately started to shift free'er and easier. Course it has gotten alot more use since I bought it then it had in years. The car runs pretty well,sure wish I didn't have the leaky rear seal though. The shiftingI can sort of deal with, but my wife has a hard time driving/shifting it.
Thanks for the reply's and Info.

Here's an off the wall thought; does the gearbox have 20/50 in it or 90 wt?
If someone mistakenly put the heavier weight in, that would make for hard down shifting. Longshot, but a cheap thing to check.

Good thought, maybe my adding a halfquart of20/50 thinned it out some. I stored it for the winter, but come spring here in "Southern" Wisconsin, it will be one of the first things I will check.

Thanks again