short Automatic Transmission Dipstick

[slowboy]

1972 GMC P/U Truck
CUSTOM 1500
350 4bbl
TH350 Transmission
REAR WHEEL DRIVE

I was checking transmission fluid and the last couple inches of the stick snapped off...the end that goes into transmission with the measurements on it.
Fortunately it broke off in my hand and not in the transmission.

While looking for a new dipstick I purchased one that I thought was right for the TH350, it said for GM TH350 on the packaging.[I think part number was 720-9764]
Only thing is, is that the new dipstick was [I returned it to Advance Auto until I can find out what's going on], 27" long from the tip to the top of the top hat, and the one I took out of my truck was only 24/25" long from the tip to the top of the top hat.
Can anybody tell me how my truck could possibly have a shorter transmission dipstick? And is this normal?
Could somebody apparently had put the wrong length dipstick in before I bought the truck?
Or is this truck known for some of them having the shorter length dipstick?

My understanding is that the TH350's pan is a square with a corner cut off... and that is the way my pan is and that's why I'm calling it a TH350.

Thanks and much appreciation for all info,

Keith [slowboy]

[HotWheelsFan]

I would say the dipstick goes with the tube and should be correct. However, aftermarket tubes may differ from stock and, or, original - just as they could have a chance of inaccuracy - as some aftermarket items can be.

With your question, I have seen several different tube lengths from vehicle to vehicle. I would think the 350 and 400 Hydromatics would have dipstick tubes that could be swapped and possibly with the powerglide and others. From my recollection I have seen the shortest tubes on the earliest vehicles and they seem to me the length got longer on some vehicles throughout the 70s to 80s.

And, you have where the full and low marks on the dipstick and where they actually are in relation to the length of the dipstick.

Many differences with many length options and more than one correct outcome. An easy answer would be to use a good dipstick - tube set and change the tube with the dipstick if you feel the length differs from your actual length.

Remember, its the fluid level in the trans that needs to be correct, not what you see on the dipstick. Use common sense, maybe a second set of eyes, or a professional if you feel something does not look right and warm fluid readings will differ from cold readings as well as some transmissions ask to be checked in neutral and some in park...

Bob

[Accelo]

"I would think the 350 and 400 Hydromatics would have dipstick tubes that could be swapped and possibly with the Powerglide and others."

The tubes and guages for all the above transmissions are different.

The correct level should be exactly at the pan gasket level. I would cut off the replacement gauge to match the old one and possibly file marks into it.
It would not have done any damage if the gauge had broken off inside the transmission.
One can purchase the tube and gauge as a set, typically with the upgraded "Top Hat" seal at the bottom. Likely the best option.
Avoid anything chrome. They almost always leak.
Cheers

[leddzepp]

Originally Posted by Accelo

"I would think the 350 and 400 Hydromatics would have dipstick tubes that could be swapped and possibly with the Powerglide and others."

The tubes and guages for all the above transmissions are different.

The correct level should be exactly at the pan gasket level. I would cut off the replacement gauge to match the old one and possibly file marks into it.
It would not have done any damage if the gauge had broken off inside the transmission.
One can purchase the tube and gauge as a set, typically with the upgraded "Top Hat" seal at the bottom. Likely the best option.
Avoid anything chrome. They almost always leak.
Cheers

Agree.

I just got done re-sealing and installing a th350 in my 68. I used an aftermarket dipstick/tube that utilizes a hat seal as opposed to the o-ring style (notorious for leaks). I’ve used them in the past and as previously NO leaks, very happy. The OEM dipstick measures 24” and the aftermarket measures 26”, at least the ones I have. Here is a pic of an aftermarket dipstick (the tube is installed on my current th350) and the OEM tube/dipstick for comparison. The important thing is to make sure the dipstick and tube combo match.

[HO455]

Originally Posted by Accelo

"I would think the 350 and 400 Hydromatics would have dipstick tubes that could be swapped and possibly with the Powerglide and others."

The tubes and guages for all the above transmissions are different.

The correct level should be exactly at the pan gasket level. I would cut off the replacement gauge to match the old one and possibly file marks into it.
It would not have done any damage if the gauge had broken off inside the transmission.
One can purchase the tube and gauge as a set, typically with the upgraded "Top Hat" seal at the bottom. Likely the best option.
Avoid anything chrome. They almost always leak.
Cheers

Good information. I will check mine next filter change.

[slowboy]

Thanks for 'ALL' of y'all's replies, very helpful!
And much appreciated!

Keith [slowboy]

[MikeB]

Dipstick length doesn't mater as long as it's matched to the tube.

If you know the original length of the dipstick that broke, just shop for another one that's the same length. FYI, I see most are shown as 27".

Best bet would be to buy a matched dipstick and tube set. I like the ones with a sleeve, like this. It also appears to be bare steel, not chrome, which IMO is hard to read (the chrome, that is). https://www.summitracing.com/parts/sum-702212/overview

[72SB]

replacement dipstick/tube can be different than original as long as tube and stick leave the correct length of stick that goes into trans

Mine has the newer fold down locking type. Got it on Rockauto

[BROWN 70]

mine broke like the op,s. went to the wrecking yard and found a gm stick that was close. trimmed it and filed a mark on it. all good.