Roadster is puking and locking up on me!!!!

O.K. gurus... I have two delemmas.

I recently installed a set of 2.18 highway gears in my quickchange and replaced the rear tires with 2 inches greater diameter (now 30 inches) while trying to get 20mpg on long hauls.

Problem is... my Turbo 400 tranny started puking up fluid through the dipstick tube and coating the whole passenger side with oil....!

I had this problem when I first got it on the road and discovered that a "Mud Dobber" wasp nest was in the vent tube. And the problem went away as soon as I cleaned the orifuss.

The Vent tube is free from debris and the outside temperatures have been very cool... my question is... could I be overheating the tranny fluid by running these gears???

Or is there something else I should be looking at...???

Next problem might be a factor to the first problem... I'm running a set of rebuilt "vintage" JFZ four piston calipers front and rear and I noticed that the rears aren't always releasing as the temperature rises... could this be the "Master cylinder"...? I've also heard that the flex lines to the rear axles can separate internally and swell themselves shut...!

I'm not running any proportioning or residual valves... but might there be some kind of valving in a corvette master cylinder that I don't know about???

Any light on these subjects would be appreciated...!

 

Hi Mark- is the filter fresh too? if not the plugging however slight will cause what you describe.... I would also suggest abot 2:50 as the highest ratio to do any good with the tire height ya have....

 

I wonder if you have a valve body leak, putting pressure into places that it dosen't belong? I had a Ford that used to blow out fluid once it got hot, if you got on it at all. It "rustproofed" the underside, and left a cloud of white smoke behind you where it was burning off the exhaust pipes. I'm glad that I wasn't behind it, I probably oiled up their car too.

 

Hey Mark! Can't remember the details but at one time GM had a problem with trannys puking out the dipstick tube and causing fires. Solution was to put a dipstick in with a positive seal where it goes into the tube. More than likely dragging brakes are putting a strain on the tranny. I don't think the tires/gears would be a problem unless you were lugging down the tranny somehow.

 

Don't know about the tranny, but a couple of things have come to light regarding dragging brakes. The fluid for my front discs were heating up and locking the front brakes. I put a heat shield on the master and heat sleeves on the brake lines. I had gone to lake style headers and the tubes that went under the chassis were too close to the master and lines.

A friend of mine just had the opposite problem with his rear brakes. Turns out the brake rod was too long, applying pressure to the system all the time. He loosened the brake rod, it dropped down and seated itself. Turns out it wasn't too long. Just was seated properly.

Rod and Custom has a great article for trouble shooting brakes in the October 2007 issue.

 

HMMMM....Using the calculator 2.18 gears X 30" tires @ 70 MPH equals 1710 RPM.

You've got to be dragging some where or else fighting a 80 mph head wind all the time

 

No thoughts on the tranny problem but the brakes:hmmmm. Seems to me those are the same calipers I had on my 68 Chevelle.Worst damn things I've ever seen.Wound up overhauling them about once a year.Pistons would either freeze in the bores or cock and leak.Finally ditched the car after taking out the left side on a cement base for a light screwing around in a parking lot.They used those calipers on early Corvettes(63-67)if I remember right.Junk.

 

I think you want the motor revving closer to about 2500. If it's too slow, you're below the power band and "lugging" the engine. Did you ever ride a 10 speed bike and leave it in high gear? That's why you got worse mileage at the lower engine speed. And you might overworking/overheating the trans with that super low gear, too.

Tracy

 

I too am not sure about the brake problem. Some good idea's have been mentioned already..
I've read the responses and thought about it myself..
If your brakes are dragging, you would be on the gas more in order to overcome the drag, thus putting more strain on the transmission and getting it hot causing the fliud to puke.
I know you said that the second problem may be causing the first..and i think you might be on the right track.
I have seen auto transmission's do exactly what your's is when they are over heated.. Be it lack of a cooler, or one that's not large enough, towing...Or, brake's dragging.
The transmission dosn't know if something's dragging or if your towing something heavy, but it will react the same way with either..it'll get hot.
Are you running a good size trans cooler? That too will aggravate the situation if it's too small..
I'm sure the highway gear's are adding to it as well. Between the added strain because of the lack of gear, combined with the brake issue..that car is probably working like it's towing a house.

i'd get the brake problem fixed first.. That *might* solve the trans problem as well..


I'm only brainstorming trying to come up with idea's to help.....
hope you get it solved soon..

EDIT....actually i had a similar brake problem on my 53 chevy a couple month's ago that i forgot all about. I was on my way to the Syracuse nats when it started to drag..enough that at a light it would hold the car.
I stopped and un-adjusted the brakes..but the actual problem was caused by me filling the master cylinder to the top the night before.
As the brake temp went up, there was no room for the fluid to expand, and it actually started to apply the brakes a touch. just enough to cause a problem..
May not be the same thing for you..But by chance have you topped off the master recently?


Cool car by the way

Tony

 

I think it has something to do with the smoke out the back......from the tires!!!!

 

Does this RPM level mean you are driving everywhere with torque converter busy multiplying? Would that do unpleasant things while thrashing your fluid??

 

Once i got back home, i adjusted the brakes back up and took a little fluid back out of the master and my problem was solved. I left the fluid about 3/8 or so down..
Did you top your's right up to the top too?
It would be great if that's what's causing your brake problem too..

 

Pull the tranny pan and I am betting you will find some clutch plate wear sludge ,in that pan and filter...probably a side effect of the tall gear & tires in addition to= OWNER ABUSE...Ha!!

 

Something else in your factor..that is... with that turbo 400 xmission, what stall converter you running with??? 2.18 is still an awfully tall gear. I'm running with a 2.43 in my roadster and doing just fine with it, 29" tires @ 70 about 2000 rpm and can still smoke the tires when I want, but it cruzes nicely with freeway traffic. with a 15 gal tank, I can go about 200 miles and still have about 3 gal left.

In the HellRaiser I've got 3.0's for messing around, with those and a 29" tire, I run about 2500 rpm @ 70 and 10 mpg. But with the 4.10's I only get about 5 mpg, and run about 3600 to get 70.