Transaxle Fluid Capacity

[richardhead]

I have searched this forum high and low for references to the actual amount of transmission fluid the transaxle, without added cooler, will accept when doing a fluid change. So, if I am duplicating a former post, please forgive me.

The service manual gives no specific reference to the amount of fluid used during a change...unless I missed it somewhere in the transaxle section. The owners manual states 4.5 quarts (4 quarts plus 16 fluid ounces).

I just changed mine, and the transaxle would only take in between 4 quarts 7 fluid ounces and 4 quarts 8 fluid ounces, before overflowing out the fill hole on the driver's side, after the following procedure:

1. Drain fluid from transaxle by removing the driver's side mechanical filter assembly and the passenger side magnetic plug. The driver's side fill plug was removed also.

2. I let drain overnight after installing Jay's GT Saver Breather, loosening the bypass line to install the breather.

3. Installed the mechanical filter plug and a GT Saver magnetic plug in place of the stock magnetic plug. Filled the transmission using a flexible hose/funnel assembly from the top. Fluid began to drain out at exactly 4 quarts of fill.

4. Put in fill plug, started and ran engine for about 1 minute to allow pump to pick up/circulate fluid. Shut off engine.

5. Removed fill plug and was able to get between 7 and 8 additional fluid ounces in the transaxle before fluid began running out of the fill hole.

6. Final result of fill was 8+ fluid ounces less than the owner's manual stated was required, or a total of 4 quarts plus 7-8 fluid ounces total, instead of 4 quarts plus 16 fluid ounces. Car is sitting Flat on all four tires.

Anyone else have a similar experience, or were you all able to get the full 4.5 quarts of oil into the transaxle before it started running out the fill hole?

I understand an additional 7/8ths quart of fluid is added to the stock amount if you add a transaxle cooler to the system.

Thanks for any input/feedback.

 

[Gimbal]

My only comment is there has to be a tolerance on the 4.5 qts. Ford does not seem to state a tolerance. I would think +/- .25qts is reasonable to assume. As long as you are getting flow out the hole you should be good. It sounds like you did everything correct in your sequence and procedure. Does the drain holes actually allow all the fluid to drain out or are they slightly higher? This could account for some of the difference too.
I will do my oil change next week and will let you know how much I was able to get in.

 

[richardhead]

Additional Thoughts on Transaxle Fill Capacity

My only comment is there has to be a tolerance on the 4.5 qts. Ford does not seem to state a tolerance. I would think +/- .25qts is reasonable to assume. As long as you are getting flow out the hole you should be good. It sounds like you did everything correct in your sequence and procedure. Does the drain holes actually allow all the fluid to drain out or are they slightly higher? This could account for some of the difference too.
I will do my oil change next week and will let you know how much I was able to get in.

8 fluid ounces is a lot of variance, anyway you look at it. It is nearly 6% short of the total stated in the owner's manual.

Now, let me postulate something which has run through my mind: Originally, as I understand, Ford was going to include a transmission cooler as standard equipment on the GT. They decided not to do so. If they would have done so, where would be the most logical place to put the additional fluid which would occupy the cooler? Why, in the transaxle initial fill, of course. A number of folks have commented on a factory "overfill issue" they have regularly observed with the transaxle fluid which may be contributing to venting of the fluid from the transaxle into the engine bay. Suppose the initial transaxle fill specification included extra fluid for the cooler, then subsequently the cooler was dropped but the fill spec was not changed? I understand the "CoolTech" cooler takes about 7/8ths of a quart extra (about 28 fluid ounces), but its hose lines and cooler internals are of a larger volume than the Ford FRPP, or "original" cooler unit. Anyone know exactly how much the FRPP cooler requires extra? I didn't measure the exact amount of oil which drained out on my change of the stock transaxle, but since I refilled empty bottles, I believe it was quite a bit more than four quarts...how much I can't recall, unfortunately. Anyway, the transaxle can easily be filled with a larger "measured" amount of fluid, versus the drain hole indicator seep, if the car is jacked up higher on the driver side when the fill is made. How much overfill would depend upon how much fluid the cooler retains, if any significant amount, when the transaxle is drained. Does anyone think Ford would actually "waste" this much expensive transaxle fluid on overfills, unless they were actually thinking it was necessary for something...like a dropped cooler? So, some food for thought when it comes to this transaxle fill capacity issue. Perhaps we could have a few more folks measure the amount of fluid which actually drains out versus what they can get back in, and report back on this thread/forum?

 

[Indy GT]

When I installed my FRPP cooler I added approximately 7/8 qt of fluid after the cooler and lines had been filled.