I just got my mav running,Should i flush the tranny?

Hi everyone.. I finally got my 1971 Maverick running and nearly drivable.

When i bought it, the guy said that as soon as i get it running, I need to take it to get a transmission flush immediately. But reading about it online, I see a LOT of people saying that doing this is a bad idea, that a flush has a high chance of destroying the transmission.


Is it a bad idea to do a flush? Or is that only for newer cars?... If you don't recommend a flush, What is recommended?

The car has been sitting since at least 1997 (that's when the tags expired). It doesn't seem to have any problems shifting (its an automatic).


Thank you for your help!

 

thats a really tough call. i think i saw a good post by paul s about that a while back. try searching the tranny section for flush

 

when i got some my tranny serviced they said if they pull off the oil pan and theres and pieces of metal ect that they would just leave it the way it was. luckily my pan was clean so they changed the fluids...

 

and congrats on getting the car running. i was wondering how the car was coming cause i hadn't heard anything for a while can't wait to see this rare maverick restored!

 

At the least I would drop the pan and drain the exhisting fluid and change the filter.If you find metal shavings(I mean pieces)not the typical fine particle stuff(looks like dust fine)Then you need to go through the trans.If its just the fine stuff...pop a new filter in it and put it together a fill it up...it cant hurt to change the fluid.Look to see if the converter has a drain plug on it if so...drain it as well.If not fresh fluid will mix with what cant be drained out of the converter kinda defeating the purpose.I wouldnt flush it untill you are certain about its condition.On an old poorly maintained trans a flush can be bad as it loosens up debris in the trans that would other wise remain unmolested for the most part.Good luck.

 

Actually, I think it CAN hurt to just change the fluid.

Not an expert, like PaulS, but I noticed a severe decrease in tranny performance after my first fluid change.

I initially thought I used the wrong fluid, but found that the fine dust floating in the fluid actually helped the clutches to catch, and when I swapped the fluid out, I removed most of it (minus the 20-25% that resides in the converter).

Then when I did a shift-kit mod, and swapped the fluid again, I got ALOT of slippage, most of which was able to be adjusted out with intermediate band adjustment. But, still, the trans is worn.

Regardless if you swap fluids or not, I think any 35 year old tranny needs to be rebuilt before being driven hard.

 

The transmission has been sitting for 11-12 years...the seals are probably disintegrated by now. Why not bebuild the trans?

 

Like I said...

 

How much does it cost to rebuild a transmission?

I don't have a garage i can use much (i use my uncles when i need one bad, But he charges me $50 a day). I've never rebuilt a transmission (my 01 jetta needed a partial rebuilt recently, and that cost me $900. It was qouted at $2000 at a good transmission shop. $900 was at the cheapest in town, and its tranny is suddenly slipping again 5 months later.), So i have no idea how much it costs to do so.

I still have quite the list of things to do to the car before i can enjoy driving it a little bit.

Right now it has a cover on it, Because the roof is still bad (need a garage and/or some nice weather to set about fixing that), and i just learned that nearly every piece of weatherstripping needs replaced (should have seen that coming.)

Thank you everyone.. Let me know on your thoughts/oppinions/experiences with rebuilding the trans.


p.s. If anyone has a garage i can use in the oregon/washington region, i'd be willing to rent space if i can fit it in my budget!

 

ok for starts never flush the tranny if knocks the junk loose and in the near future it smokes your tranny and for cost, 700 is reasonable for a c4 and its almost 100% labor, we maybe spent $50 for parts and we shift kitted it. I know all of this because my dad owns a transmission shop where my mav sits and i blow all of my time.
-chase

 

A drunk monkey could rebuild a C4. Draining & filling the convertor & trans is no different than putting it on a flush machine. If the fluid on the stick is black, just get the trans rebuilt. If you change the fluid it will slip terribly. The other guys pretty much told you the same thing, just at different times! LOL.

 

A c4 rebuild is pure gravy. Short of a powerglide they dont get any simpler.Not an expensive job at all and well worth the effort. If it shifts ok just leave it alone. If it starts to flare up between gears rebuild it.

 

I was quoted $800 if I pull it and install it, and with a new converter. I think they only charge another $100 to take out and install it. Guaranteed to 400 hp, so not race quality, but fine for how I intend to use it.

 

I had my c4 re-built. I took it out and replaced it. $500. I dropped it off one day and it was ready the next day

 

Thanks everyone. I will go with that (either doing it myself, or paying someone to do it)... It'll be fun trying to get it out. I'll have to buy an engine hoist, since i have seen that you can't easily pull an automatic out without using a hoist.


Do you think it would be safe to drive it once or twice before then? I mean, If i'm going to rebuild the transmission anyways...

I am just kind of eager to drive it to work for a day or two... Show it off a bit on some of the dry days we have coming up, up here. I've been waiting to get it running for a good 4 months. Haha.

It will take me a month or two to save up the money to do it. I may sell my van to fund it. But if i do that, I don't know what i will use to carry parts around in. Haha.