Transmission "flare-up?"

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DartSportDude

Old school A-body owner
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Just recently, my 73 Dart Sport 340 with 727 TF tranny has started to act strangely when shifting between first and second. The tranny acts like it can not shift, or is slipping, and the engine revs. You have to let off the gas a bit and baby it to get it to shift. The problem seems to go away after a couple of shifts and everything warms up.

Any idea what could be causing this problem, and if there's an easy fix? I sure hope I'm not looking at a tranny rebuild!

Thanks!
 
First thing I would do, as I have done before, is to drain the oil and replace it with a better brand... I remember I used Bel-Ray ATF and problem was solved! Hopefully it is something that simple, I wish you luck.
 
No sorry it was not Bel -Ray, I cannot remember, it was 11 years ago, I remember it was ATF I bought from a motorcycle shop...
 
If you have a insulation pad underside of the hood look for a mouse nest mess under the kickdown linkage.
I saw talk from drag racers about John Deere hydrolic oil being great trans fluid (different forum).
 
As you've suggested, I thought we start with a transmission fluid change. Do you think the fluid could really be to blame for the flare-up between first and second?
 
Hopefully it is, I had the same problem 11 years ago and it was due to the ATF. I had just reinstalled my 198ci with the tranny after several years it was in the basement. The first month was a hell with the problems I had to overcome and I remember vividly the flare up between 1st an 2nd because I knew that if the tranny needed rebuilding that would mean the end of it... you see it was almost impossible to find parts for my Duster back then and that oil change saved me!!
 
In your case (slippage, engine revving, etc) I think you'll be extremely lucky if a fluid change fixes the problem. But hey, I hope that's all it is. A leaking or blown internal seal could do what you describe. Other things to check: Fluid level while idling in neutral, kickdown linkage for proper adjustment and travel.
 
99% chance Preston is wright! I guess my ATF was probably just crap. Here is a short list for you:

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I would start with a fluid change and band adjustment. The front band (which is the adjustment on the outside of the case) can drastically affect how it shifts and cause flair up like you described. If when you drop the pan inspect what remains in the bottom of the pan after draining the fluid off. If there's alot of clutch material (looks like mud) or brass flakes your do for a trans. rebuild. If not the adjustments may cure it. Also check you throttle pressure linkage for correct adjustment.

I would not recommend using Hy-gard or any other hydraulic oil in an auto trans. I worked for Hyster forklifts for 11 yrs. and their hyd oil although used in their transmissions was about equal to 10 weight oil. Much thicker than regular ATF. Also it had different friction modifiers in it that were not compatible with certain friction materials. I personally don't know the formula for Hy-gard but I'd bet it's similiar. If you put it in it may work for awhile but more than likely cause damage before long.
 
i had a neon do something similar a few months ago i just dropped the pan changed the fluid and filter but it wasnt really slipping just didnt want to upshift. My dart was doing the same thing though when i first got it. It was low on fluid i did the same thing dropped the pan changed the filter and fluid and has worked fine ever since but i got lucky that it hadnt been doing it for too long. I would agree with what everyone is saying though if you drop the pan and after you drain the residual fluid from the pan if the bottom of the pan is black and had a lot of clutch material you will probably be looking at a rebuild but if you caught it soon enough you may get by with a filter and fluid change. Good Luck Justin
 
RedFish said:
If you have a insulation pad underside of the hood look for a mouse nest mess under the kickdown linkage.
I saw talk from drag racers about John Deere hydrolic oil being great trans fluid (different forum).
Click to expand...

Could they have been talking about using it in a manual trans? I could see it working in there.
 
For longer than usual times to upshift, or doesn't seem to want to upshift, low fluid and bad filter are usually the culprits. Reving thats a diiferent story, especially since the upshift problem seems to stop after a few shifts. This would be after the transmission has warmed up and the everything has expanded with the heat possibly reducing the problem somewhat until it starts off cold again. I see a rebuld in your future. I have been there. Now I change the fluid and filter when recommended and a flush every couple of years.
 
Wow, great input guys. That's what's so cool about this site! My mechanic is dropping the pan today; hopefully there will be no residue and a simple fluid change will solve the problem. The upshifting problem just started, so maybe I caught it in time. However, I basically have no luck when it comes to problems like this one, so I'll no doubt be looking a rebuild.

Question: what do you think would be reasonable price to expect for this kind of rebuild?

Thanks again!
 
Totally depends what's wrong, from a $100 oil and filter change to $2000 for a complete overhaul (time and material) if the bands are shot. During a major I would replace everything that can wear including the pump and go with a new bolt in sprague.

Terry
 
Terry's right about replacing everything when you rebuild it. That includes all thrust washers, bushings, bands, steel and friction plates, new sprague rollers and springs or complete bolt in sprague, and most importantly setting all the clearances correctly. If you do need a rebuild and he's over $700 (not counting R&R) I'd suggest looking into either Andrews Racing transmissions or Cope Racing Transmissions to get one. Not sure on Andrews but I know CRT has street versions (rebuilt correctly by real Mopar people) starting at $700-800. I can absolutely guarantee you'll get a top notch transmission that will now only perform great but last longer if you go with either of these companies.

Make sure he checks that front band adjustment. A loose front band can do just what you described. Good luck.
 
I had a 998 lockup trans (similar to a 904) rebuilt just over 3 years ago. It cost me $195 for labor & $280 for parts. This included replacing the torque converter, a "shift improvement kit" & I did all of the R & R. They also flushed the trans cooler in the radiator & my aux. cooler. I flushed out the trans cooler lines myself. I knew a person who had a similar job done a couple of years before that & it cost about $900 with the shop also doing the R & R. This was in a 4wd vehicle, so R & R for yours would probably be less.
 
my first tranny cost $600 and it killed 2 engines before i put another tranny in from a different shop for $1500. you get what you pay for.
 
Good news: the ATF fluid and filter change did the trick. Tranny shifts perfectly now. Guess there's a lesson here: Don't forget about those fluid changes!

Thanks again to everyone for your help.
 
Glas to hear it. That is something too many people easily overlook. The problem comes in where most opperators manuals say you don't need to replace it unless you tow or do alot of city driving. That's hogwash. It still needs to be changed every 50,000 miles or so. And at the same time you should ALWAYS adjust the bands and that will make it perform better and last much longer.
 
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