Transmission Dipstick Tube Leaking - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TheWhiteElephant · 10-20-2010, 11:25 PM

My TH350 has a serious leak at the transmission dipstick tube o-ring where it inserts into the tranny. I bought a Hughes Performance tube and dipstick assembly from Summit but it doesn't fit properly--it needs to be longer. I didn't really want to replace it with an OEM style tube or a braided stainless steel Lokar unit (looks too fancy), but it looks like I'm going to have to go with the Lokar 36" unit. It has a dual o-ring seal and is a firewall mount.

I could fit a replacement o-ring in there but I know these tubes are notorious for leaking. The nice thing about the Hughes unit was that it had a press-in type seal that looks like it performs better than the o-rings, but again, it doesn't fit properly.

Anyone have any solutions to this problem that I could try out?

Thanks in advance,

Mando

hotrodimpy · 10-21-2010, 12:53 PM

Mondo.
We would love to have you purchase a Lokar product. Our standard firewall mount dipstick is 24" long. We also make a 36" long firewall mount dipstick.
We see this problem quite often. You might want to check the hole in the transmission case. if it is accessable enough for you to measure it should be
.750 diameter. We see these as big as .760 diameter and nothing wants to seal. If you want to go with a stock looking dipstick look for something a little later model with the top hat style lower seal they are much more forgiving in the oversize holes. We also offer a locking transmission dipstick that has the bottom fitting installed into the transmission under compresion. All of our Stainless Steel dipsticks are available in "BLACK" and it kind of blends with the engine compartment. If you have any queations we can help you with please contact our Tech department at 865) 469-7440 Thanks Impy

babyJay · 10-21-2010, 12:54 PM

Permatex.

3r!c84 · 10-21-2010, 01:11 PM

Put some rvt around the tube and shove it in and wait for it to seal.. Maybe?
Posted via Mobile Device

Jonboy · 10-21-2010, 02:09 PM

What's wrong with the OEM part? They redesigned the tube and dipstick in the late 80's to address the leaking and trans fluid puking problems. The new tube has a boot seal, and works well. The corresponding dipstick has a locking seal at the top to keep fluid from overheating and coming up past the top of the tube. All of the parts needed should be $20-30 at the dealer.

10-20-2010, 11:25 PM	#1
TheWhiteElephant God is good! Join Date: Sep 2010 Location: Texas Posts: 689	Transmission Dipstick Tube Leaking My TH350 has a serious leak at the transmission dipstick tube o-ring where it inserts into the tranny. I bought a Hughes Performance tube and dipstick assembly from Summit but it doesn't fit properly--it needs to be longer. I didn't really want to replace it with an OEM style tube or a braided stainless steel Lokar unit (looks too fancy), but it looks like I'm going to have to go with the Lokar 36" unit. It has a dual o-ring seal and is a firewall mount. I could fit a replacement o-ring in there but I know these tubes are notorious for leaking. The nice thing about the Hughes unit was that it had a press-in type seal that looks like it performs better than the o-rings, but again, it doesn't fit properly. Anyone have any solutions to this problem that I could try out? Thanks in advance, Mando

10-21-2010, 12:53 PM	#2
hotrodimpy Registered User Join Date: May 2010 Location: Knoxville TN Posts: 120	Re: Transmission Dipstick Tube Leaking Mondo. We would love to have you purchase a Lokar product. Our standard firewall mount dipstick is 24" long. We also make a 36" long firewall mount dipstick. We see this problem quite often. You might want to check the hole in the transmission case. if it is accessable enough for you to measure it should be .750 diameter. We see these as big as .760 diameter and nothing wants to seal. If you want to go with a stock looking dipstick look for something a little later model with the top hat style lower seal they are much more forgiving in the oversize holes. We also offer a locking transmission dipstick that has the bottom fitting installed into the transmission under compresion. All of our Stainless Steel dipsticks are available in "BLACK" and it kind of blends with the engine compartment. If you have any queations we can help you with please contact our Tech department at 865) 469-7440 Thanks Impy

10-21-2010, 12:54 PM	#3
babyJay Arrived on a Pale Horse Join Date: Mar 2007 Location: SnagTown Indiana Posts: 2,524	Re: Transmission Dipstick Tube Leaking Permatex. __________________ Jason 87 V30 350TBI/400 White w/Boss V-plow 89 R3500 CC SRW

10-21-2010, 01:11 PM	#4
3r!c84 Badass Join Date: Jan 2009 Location: lox. fl Posts: 4,586	Re: Transmission Dipstick Tube Leaking Put some rvt around the tube and shove it in and wait for it to seal.. Maybe? Posted via Mobile Device __________________ Think outside the box? -84c10 (1stcar)→My Build← -00 Saturn 5spd drop a gear and disappear! 1/4:13:90

10-21-2010, 02:09 PM	#5
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Transmission Dipstick Tube Leaking What's wrong with the OEM part? They redesigned the tube and dipstick in the late 80's to address the leaking and trans fluid puking problems. The new tube has a boot seal, and works well. The corresponding dipstick has a locking seal at the top to keep fluid from overheating and coming up past the top of the tube. All of the parts needed should be $20-30 at the dealer. __________________ 1974 Jimmy- 5.3/4L80e/NP241



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