[GoGoat]

My friend has a T400 he is putting in place of a 2 speed. It was rebuilt by tranny shop and didn't have a dipstick or tube. I gave him one from another T400 I had. How do we know if level is correct? Engine and tranny is out of car now so it might be easier to confirm dipstick.

[steve25]

Unless you have a dip stick and tube out of a 70s front wheel drive Olds Tornado then there was only two other lenght set up's I know of.

If what you have there comes up to close to the level of the rear of the passenger side valve cover then you have the normal A, B and F body set up.

[mzbk2l]

Are you asking how to do it, or just asking for measurements? I don't know the measurements for a TH400, but if someone here has another one available to provide the dipstick measurements (or you can find a reference online), just compare that the measurement to the splitline of the trans with the the one you have. Here's one I was checking in a bus when we made some changes; the bottom of the scale is at the splitline and I'm measuring the height to the dipstick markings. (I had a drawing to reference for the measurements.)

[Half-Inch Stud]

After being filled and driven (with 2-3 upshifts), and refilled, the fluid should just barely drip out the Vac Mod hole when Mod removed.

So, calibrate your dip stick to that. could represent "overfilled" and if so the vent tube will puke it out, so add a rubber hose to the vent tube, tucking behind the Vac Mod for trapping the hose, and let the hose reach to the Pan floor, and cut level to pan floor. It's a dry idea.

[geeteeohguy]

Originally Posted by Half-Inch Stud

After being filled and driven (with 2-3 upshifts), and refilled, the fluid should just barely drip out the Vac Mod hole when Mod removed.

So, calibrate your dip stick to that. could represent "overfilled" and if so the vent tube will puke it out, so add a rubber hose to the vent tube, tucking behind the Vac Mod for trapping the hose, and let the hose reach to the Pan floor, and cut level to pan floor. It's a dry idea.

THIS^^^^. Properly full, the fluid will just barely drip out of the vacuum modulator hole when you pop the modulator off.

[Schurkey]

Originally Posted by Half-Inch Stud

the fluid should just barely drip out the Vac Mod hole when Mod removed.

Originally Posted by geeteeohguy

THIS^^^^. Properly full, the fluid will just barely drip out of the vacuum modulator hole when you pop the modulator off.

If you do this when the engine has been shut-off overnight, the fluid will pour out. Torque-converter drainback will over-fill the pan, which is why you check trans fluid with the engine running.

I'm expecting that they're pulling the modulator out immediately after shutting-down the fully-warm engine/transmission.

Also assumes the vehicle is level front/rear, and left/right, and hasn't had the engine/trans tilt altered from stock via racing motor mounts or somesuch. Clearly, you couldn't jack-up the front or the side of the vehicle and cram a jack-stand or two under it while you pull the modulator.

Confirmation, H.I.S?

Overall...this is NOTmy first choice for verifying trans fluid level.







If this was me, I'd
A. Find a dipstick tube that fits the engine/trans--has the welded-on mounting bracket in the right place, correct bends, etc.

B. Shove the dipstick into the tube. See how much pokes out the transmission end. Compare the amount of tube that gets crammed into the trans case, so that the "Full" mark on the dipstick is level with the pan gasket when the tube is (eventually) properly inserted into the trans, and the dipstick is properly inserted into the tube.

C. While you're doing all this dicking-around with the dipstick tube, make sure the tube isn't cracked where it's rolled to form the O-ring groove that seals it to the case. IF (big IF) you have a choice, get a tube that uses the newer "top hat" seal rather than the O-ring.

[Half-Inch Stud]

Yez. Overall, i insist that attaining the correct level in a fresh, dry TH-400 install needs careful attention.

Back in the day, i'd use the taller Big Car Dipstick tubes for ease of service. Good O-ring, no sealers.

These days, the "modern" dipstick tubes which use the grommet are superior in leak free operation.

[GoGoat]

Thanks for all replies. I like Schurkeys way to establish level. Maybe we will double check level after getting up and running with modulator level method.

[kyle_blake]

I think if one cross referenced the year of trans and go to parts store, and say hi i need a new dipstick they sell you one from transdapt?? the correct tube and dipstick(granted is sport racing chrome though).

I lost my oil dip stick and did the above. I verified the measurement of the dipstick from another 69 gto car owner with stock oil pan and was exact match for the trandept/tansdept one I was sold so I called it a day and moved on?

Food for thought?

[Scott65]

Pull the pan with the dipstick properly installed and check that the full mark is 1/4" above the pan rail.

[hobbygto65]

First of all the engine has to be running in order to check the fluid level. In neutral . If the dipstick is original to the tube you should be ok
You just have to worry about it fitting the car.

[Scott65]

Originally Posted by hobbygto65

First of all the engine has to be running in order to check the fluid level. In neutral . If the dipstick is original to the tube you should be ok
You just have to worry about it fitting the car.

Agreed, but to check the accuracy of the mark of a non original tube and stick would be prudent. Won't matter if the engine is on or off if the measuring device is wrong.

[hobbygto65]

They should all be the same, just upper part length and shape is different. The only thing that would be different is the depth of the pan. And that shouldn't make a difference.

[chuckies76ta]

So just a little clarification. My understanding is fluid 1/4" above the Transmission pan rail, engine running, hot fluid. Thoughts? Thanks

I understand the thread is about measurement of the dip stick itself.

[Verdoro 68]

Originally Posted by Scott65

Agreed, but to check the accuracy of the mark of a non original tube and stick would be prudent. Won't matter if the engine is on or off if the measuring device is wrong.

Originally Posted by hobbygto65

They should all be the same, just upper part length and shape is different. The only thing that would be different is the depth of the pan. And that shouldn't make a difference.

The should the be same, but they aren't. Aftermarket TCI dipstick. Same length dipstick out of the tube, different measurement markings. Pretty sure I ran my last transmission a quart low for years because I never checked this until Holeshot71 prompted me to recently.

[Scott65]

Yep. Hopefully the OP will verify whatever he ends up using. Doesn't take much effort to check if you're starting with a transmission that's empty.

[Schurkey]

Originally Posted by chuckies76ta

So just a little clarification. My understanding is fluid 1/4" above the Transmission pan rail, engine running, hot fluid. Thoughts?

I thought the fluid was supposed to be level with the pan gasket. But I'm prepared to learn something.

And it may be that 1/4" difference really doesn't make a difference, given that the vehicle when in motion is going to be subject to G-forces that will move the fluid around.

Originally Posted by chuckies76ta

I understand the thread is about measurement of the dip stick itself.

Well, the stick in relation to the tube it's used with.

[Quad]

Motor Trend article; What Causes Automatic Transmission Failure? 7 Ways to Destroy a Transmission

1. Your Dipstick Is Wrong

Link below

https://www.motortrend.com/how-to/ca...C44306ACA475AB

[GoGoat]

One more question. The tube I gave him has the strap that must go in a head bolt hole. But his head dosn't have a hole that matches. His motor is a 68 400, and my tube was from a 455 from a 71 or a 75? On my 69 T400 the strap goes to the top tranny hole.

[Schurkey]

Warning: Bud Light is a totally-wrong kind of tranny fluid for Turbo Hydramatics.