QuestionWhat about it slipping when it upshifts, can dirt or a clogged filter cause that problem also.
I definitely appreciate your opinion about leaving the car alone as is. When I was looking for a chevelle I was looking for something to clone into an SS. When I found this car after driving home from the first time I looked at it I said I would be nuts to do all that stuff. The car does have a V-8, 307 in it. I few years ago I took a 78 chevy pickup and did all kinds of crazy stuff, chrome, lifts, powder coating S.S. under thw hood and my favorite 383 in it. NOw I have the itch to put one in the chevelle. I plan on keeping all the original stuff taucked away in the corner such as the 307 & the P/G if I do follow through. I am not one of those guys who would go crazy with the car as I know that this engine will more than double the horses that it produces now. I know all the sway bars, shocks and spring rates are different. But I never intend to go 60 MPH through an s turn or never even would consider drag racing the car. It is just something about the idle knowing that when you hear a 383 that it is a worked engine. I know originallity means value, but help me out, how does a malibu compare to an SS all original, obviously the SS is worth much more. But being around cars and such if I ever do want to sell it which I never intend to, I will say I do have all original matching # componenets. That is what most car nuts are after. And no, you do not need to worry about me shooting the messenger. Look forward to your reply.
Thanks,
Chris
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Followup To
Question -
I have a 1970 chevelle, Malibu with a PG trans.
Recently, going up a hill I kicked it down, it went to up shift and then quickly downshifted and then got stuck in low gear. The car did sit for 3 hours then started to work fine again. Drove it to work the next day, 20 miles and worked fine. Half way home from work it started to slip in when it shifted to high gear. I did change the modulator, do have vacuum in the line, proper fluid level etc. What do I do next, can I change the tranny filter ? It is odd that it fixed itself one time. Keep in mind the car has 38000 original miles on it. I am planning on putting a 383 small block in it with a TH-350 trans, however I was not planning this so soon. How can I adjust the clutches or whatever is causing the high gear slippage problem. Is there anything else I can check?
Chris
Chris,
Answer -
Hi, Chris;
It seems most likely to me that there is a circulating particle of dirt that has gotten into the valve body or the governor and is causing trouble in the shift control, probably lowering the throttle pressure. You can check the band adjustment and the kickdown linkage for proper adjustment, but my guess is that you are going to have to take the pan down and clean out the filter - and if you find a lot of crud in the bottom of the pan, you may have more serious problems that require a transmission guy to take care of.
I don't have my books handy at the moment to give you step by step procedure for the adjustments, because they are at my shop and we're entertaining guests today, but I will get down there this afternoon and get the material and post a second reply to you with more information.
I urge you to reconsider modifying your car. There is more to an engine swap than you may realize, if you want to do it right, especially for a swap to a "383", which is a high performance engine. The brakes and other chassis parts on your car were designed to deal with a 6 cylinder engine, so both the weight difference (if any) and the performance difference (considerable) will be too much for that car.
The rest is my personal opinion - ignore it if you wish, but I think that if you want a V8 Chevelle - you should buy one, but don't ruin a beautiful, rare, original, low mileage, perfectly capable 6 cylinder Chevelle!
Now, don't shoot the messenger!
I'll get back to you with more on this later today or perhaps tonight.
Dick
AnswerI apologize for misreading your original question - I got you confused with a guy who was taking a mint original family owned very low mileage car and "upgrading" it from a 6 to a monster motor. I didn't realize your car already had the V8 - so my comments were a little too strong for your situation.
To answer your question, yes, definitely, a plugged filter can cause slippage, because if the front pump is starved for oil due to a restriction of any type in the pump inlet (which comes directly from the filter) the apply pressure to the clutchs can be reduced to the point where they will slip. Dirt in the governor can confuse the shift valves by not reporting the exact speed, and cause problems in the shift pattern also - I'm not certain that would cause slippage, unless the shift is coming too early, before the throttle pressure is up to what is required for a clean crisp shift.
Anyway, the filters are probably available and cheap, as are the gaskets, but even if you have to wash out and re-use the original filter with kerosene or diesel fluid, it isn't a big job - and it cannot hurt the tranmission to take down the pan, clean it out, and give it a fresh batch of transmission fluid. If there is a lot of band material in the pan, or if you see brass shavings in the muck, I think you are probably on the way to a transmission overhaul. To do a really thorough job at cleaning it out, drain the converter also (rotate the crank until you find the drain plugs, loosen one to provide an air vent, and then rotate the crank another 180 degress to get at the other plug, then drain it completely.)
If that doesn't cure it, you should do a band and throttle linkage adjustment.
Dick
