Thread: 700r4 dipstick tube

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What is the minimum length (heigth) a trans dipstick tube can be?

Tom,
Not sure what you're looking for, but you need a dipstick made for the 700R4. That way the level of the stick relative to the tube is right for the transmission. All of the performance tranny shops sell them, and you can find them at Summit, JEGS, Speedway, etc too. Trying to mark one yourself is going to be a big hassle if you have any type of cooler hooked up. Lokar makes several different lengths to fit different body styles, from "shorties" to almost 3' long. Others have a variety of tubes with "improved" sealing and locking sticks for high performance, high pressure applications where extreme line pressures might blow the dipstick during shifts.

You could get away without one if you need to. Wouldn't make it easy to check the level but you could use an expansion plug to fill the hole...
expan plug.png
Here's a link to McMaster Carr or any local hardware should have them...
McMaster-Carr

You could also cut down an existing tube and simply shorten the dipstick to fit. Remark the full level on the "new" stick and call it good. Probably be an inch high to leave room for the dipstick cap to seal on.
Mark

Originally Posted by astroracer

...You could also cut down an existing tube and simply shorten the dipstick to fit. Remark the full level on the "new" stick and call it good. Probably be an inch high to leave room for the dipstick cap to seal on.
Mark

The thing is you need a 700R4 tube & stick as a starting point to know the right fluid level, right? Unless I totally misunderstand, different transmissions have specific fluid levels relative to the case. You can modify a Ford dipstick just fine, but then wouldn't the fluid level need to be measured from a GM 700R4 stick and then cut accordingly? The "critical" measurement is top of tube to the "Full" mark, IMO, because that will then be right for proper level relative to the filter and fluid pickup in the tranny. Please correct me if my thinking is flawed.

The OP doesn't mention whether he has a tube and stick or not. He just wanted to know how short it could be. If he has one he's all set. Cut the tube down to the height he needs and simply cut the stick the same amount. Use the bottom of the old stick to re-mark the "new" one...

If you have the trans in and the fluid level correct, or access to a car that has the same trans, and dip stick configuration, meaning length.

With the engine off pull the trans dip stick, wipe it dry, reinsert the stick. Pull it out and see how far up on the stick the fluid is. With the motor off and cold the level of the trans fluid rises, drains back from the torque converter is the reason that happens.

Using the dip stick and starting where it rest when seated in the tube, measure down to the fluid. Subtract an inch or so and cut the tube down that much.

With the same measurement, from the bottom or end of the stick come up that amount and cut the stick. Transfer the low and full markings to the modified dip stick.

Sounds confusing but really is not, shorten the tube from the top down. Shorten the dip stick from the bottom up the same amounts.

Originally Posted by TomJ

What is the minimum length (heigth) a trans dipstick tube can be?

Tom,
If, like Astroracer says, you're simply asking how short you can cut the tube it only has to be long enough to contain any OEM "zig-zag" that's at the top of the stick to hold it straight, a couple of inches or so. Just shorten it as noted in several of the posts here to keep your level marks straight.

Thanks guys. I have one of the braided stainless lokar types now and want to clean up the firewall some. I want to put a stock tube on and cut it back to have not too much protrude past where it mounts to the bellhousing. I thought maybe the trans pushed oil up the tube while running. I see some racing rules require a locking dipstick so as the dipstick cant be thrown out of the tube.

http://www.clubhotrod.com/attachment...swap-eng31.jpg

Originally Posted by TomJ

Thanks guys. I have one of the braided stainless lokar types now and want to clean up the firewall some. I want to put a stock tube on and cut it back to have not too much protrude past where it mounts to the bellhousing. I thought maybe the trans pushed oil up the tube while running. I see some racing rules require a locking dipstick so as the dipstick cant be thrown out of the tube.

Tom, the transmission can indeed push oil up the tube under high loads, like a high rpm shift. I think that I'd opt for one of the locking dipsticks if I were going super short, and I hadn't thought before about needing to keep some form of tube bracket/brace that usually attaches to a bellhousing bolt to keep the tube in place. Without that the whole tube could blow out of the tranny case and blow fluid all over. Your firewall mount does that now.

Yes, they will that is known as a thermal event, locking dip sticks are required on 10.99 sec and quicker cars NHRA 2010. Seems a little stupid cause the trans vent can still puke fluid from the same event.
The fluid rise I was speaking of is normal and is readily seen, looking for and measuring that will give or demonstrate how much you can cut.

Cut the tube and stick on the 32 truck, 350 turbo trans used the method posted. Wanted to keep the OEM assembly, that lokar is crap hard to read, add trans fluid you need an eyedropper. If I could figure away to remove the lokar from the 34, would do it in a heart beat.