Speedo Leak - Bullet Replaced - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cebra · 03-05-2018, 11:03 AM

I replaced the bullet on my TH350 and it is still leaking heavily. When I pulled the bullet, the speedo gear came with it and during reinstall, I noticed the gear was fairly loose in the bullet. I don't see anything stopping the flow from going between the speedo gear and the bullet and leaking out where the cable threads onto the bullet. I also bought a seal (ATP 2034 Speedometer Seal) but do not know where it goes, I assumed the new bullet includes this seal already. Any information or a schematic from cable to speedo gear would be great. I think I am missing a seal somewhere. Thanks.

geezer#99 · 03-05-2018, 12:19 PM

If that seal is a small o-ring it goes inside the bullet.
For some reason the new bullets don’t come with them installed already.

cebra · 03-05-2018, 01:54 PM

That could be it, I thought the new bullet already had the seal in it so I didn't use this one. I will need to pull it out and check. On a side note, there are like 50 threads on speedo seal leaks which is how I found out about the bullet replacement but not much further. Here is a pic of the seal I have:

geezer#99 · 03-05-2018, 02:15 PM

That’s the one.
I used a wood dowel to tap one into place.
Put a little oil on the gear when you slide it thru. Helps keep the seal from burning out on first use.
If it doesn’t stop the leak then you might need to replace the gear. They sometimes get a groove cut in them by that seal. Just a remote possibility of that.

cebra · 03-05-2018, 02:27 PM

Excellent, thanks so much.

cebra · 03-05-2018, 02:30 PM

Oh, just so I am sure, this is going in the back of the bullet (the threaded side) and the metal part of this seal is the part you tap in (the rubber going into the bullet)? Thanks.

**ga-stepside** · 03-05-2018, 03:19 PM

Quote:

Originally Posted by cebra

Oh, just so I am sure, this is going in the back of the bullet (the threaded side) and the metal part of this seal is the part you tap in (the rubber going into the bullet)? Thanks.

Like this:
Name: bullet.jpg
Views: 870
Size: 30.1 KB

1969 Project · 03-05-2018, 05:03 PM

Quote:

Originally Posted by cebra

I replaced the bullet on my TH350 and it is still leaking heavily. When I pulled the bullet, the speedo gear came with it and during reinstall, I noticed the gear was fairly loose in the bullet. I don't see anything stopping the flow from going between the speedo gear and the bullet and leaking out where the cable threads onto the bullet. I also bought a seal (ATP 2034 Speedometer Seal) but do not know where it goes, I assumed the new bullet includes this seal already. Any information or a schematic from cable to speedo gear would be great. I think I am missing a seal somewhere. Thanks.

Where did you order these from? I just noticed mine started to leak as well.

geezer#99 · 03-05-2018, 06:12 PM

Quote:

Originally Posted by 1969 Project

Where did you order these from? I just noticed mine started to leak as well.

You can get both here or visit your nearest transmission shop.

https://transmissioncenter.net/?swoo...-gears&paged=1

cebra · 03-06-2018, 12:49 PM

Quote:

Originally Posted by 1969 Project

Where did you order these from? I just noticed mine started to leak as well.

I ordered mine off of ebay. The seal is on rock auto for 50 cents but their shipping is very expensive. The ebay seller I got mine from was a transmission shop. Bullet was $7, seal was $5.

1969 Project · 03-06-2018, 02:09 PM

Quote:

Originally Posted by cebra

I ordered mine off of ebay. The seal is on rock auto for 50 cents but their shipping is very expensive. The ebay seller I got mine from was a transmission shop. Bullet was $7, seal was $5.

Do you happen to have a link?

**ga-stepside** · 03-06-2018, 02:45 PM

I got mine 2 years ago off EBay, worked perfect no leaks since.

https://www.ebay.com/itm/TH350-TH350...QAAOSwMvtZVSOA

1969 Project · 03-06-2018, 04:08 PM

Quote:

Originally Posted by ga-stepside

I got mine 2 years ago off EBay, worked perfect no leaks since.

https://www.ebay.com/itm/TH350-TH350...QAAOSwMvtZVSOA

Thank you sir

hotwls13 · 06-20-2018, 12:51 PM

Quote:

Originally Posted by ga-stepside

Like this:
Attachment 1759776

Does anyone know the factory "driven Gear" for my truck?? Or where I can find it? I have 3.07 rearend. 1970 GMC 1500 5.7 with TH350.

I'm trying to have all the parts BEFORE I start tearing things apart.

It looks like my Trans is leaking from everywhere (pan, speedometer gear housing, shift shaft and possibly more). I have all the seals/gaskets and filter to seal up the other areas. Picking up a new Gear Housing at lunch from local Trans Parts shop. They have "some" drive gears. Figured I'd grab a couple in hopes I get the right one.

I'm not so worried about speedometer accuracy at this point, just want to stop the bleeding (new truck to me, haven't gotten it on the road yet).

I jacked up the front of the truck a couple nights ago (engine is also leaking). Now getting lots of leakage out of speedo housing.

I'm assuming I can drain the whole trans by removing the speedo gear housing with truck on front jack stands?? Then move onto pan and shaft seal.

slikside · 06-20-2018, 01:21 PM

Sub'd.

67 chevelle · 06-20-2018, 03:36 PM

Sometimes the "driven gear" gets a grove in it on the skinny end , where the oring rides , if it does it needs replaced

hotwls13 · 06-20-2018, 04:17 PM

Quote:

Originally Posted by 67 chevelle

Sometimes the "driven gear" gets a grove in it on the skinny end , where the oring rides , if it does it needs replaced

Yep, My trans is literally leaking from every seal, gasket, oring etc. I figure I may as well just track down a new drive gear so I have it beforehand. Tried the local trans parts house but they only had the larger 2" ones.

I've found them online but I'd rather not wait for the wrong part. Gonna try AutoZone (they are closest to my house but a bunch of button pushers) and Oreily's. If I strike out I'll just pull everything and order the gear I need after.

1969 Project · 06-20-2018, 05:34 PM

I used a 9 tooth drive gear (green) and a 19 tooth Driven gear (natural) and my speedo is right on the money. The overall size of your tire also comes into play. You can get them at your local tranny shop or here http://www.laspeedometergear.com. He was pretty helpful when I spoke with him. Good luck!

hotwls13 · 06-20-2018, 06:16 PM

Quote:

Originally Posted by 1969 Project

I used a 9 tooth drive gear (green) and a 19 tooth Driven gear (natural) and my speedo is right on the money. The overall size of your tire also comes into play. You can get them at your local tranny shop or here http://www.laspeedometergear.com. He was pretty helpful when I spoke with him. Good luck!

Yeah I wasn't planning on pulling the tail (so I won't know what color,or how many teeth) my drive gear has. Thought maybe there was a "standard" for 350 with 3.07 gears. :/

jmj4 · 06-21-2018, 09:01 AM

Quote:

Originally Posted by hotwls13

Yeah I wasn't planning on pulling the tail (so I won't know what color,or how many teeth) my drive gear has. Thought maybe there was a "standard" for 350 with 3.07 gears. :/

If you pull the speedo bullet, you can see the drive gear inside the tail housing with a flashlight to determine the color. You can look up number of teeth and go from there.

hotwls13 · 06-21-2018, 09:11 AM

Quote:

Originally Posted by jmj4

If you pull the speedo bullet, you can see the drive gear inside the tail housing with a flashlight to determine the color. You can look up number of teeth and go from there.

Awesome!! I wasn't sure if that was a possibility. Thanks for that pic.

03-05-2018, 11:03 AM	#1
cebra Registered User Join Date: Jan 2018 Location: Durham, North Carolina Posts: 782	Speedo Leak - Bullet Replaced I replaced the bullet on my TH350 and it is still leaking heavily. When I pulled the bullet, the speedo gear came with it and during reinstall, I noticed the gear was fairly loose in the bullet. I don't see anything stopping the flow from going between the speedo gear and the bullet and leaking out where the cable threads onto the bullet. I also bought a seal (ATP 2034 Speedometer Seal) but do not know where it goes, I assumed the new bullet includes this seal already. Any information or a schematic from cable to speedo gear would be great. I think I am missing a seal somewhere. Thanks.

03-05-2018, 12:19 PM	#2
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,512	Re: Speedo Leak - Bullet Replaced If that seal is a small o-ring it goes inside the bullet. For some reason the new bullets don’t come with them installed already.

03-05-2018, 01:54 PM	#3
cebra Registered User Join Date: Jan 2018 Location: Durham, North Carolina Posts: 782	Re: Speedo Leak - Bullet Replaced That could be it, I thought the new bullet already had the seal in it so I didn't use this one. I will need to pull it out and check. On a side note, there are like 50 threads on speedo seal leaks which is how I found out about the bullet replacement but not much further. Here is a pic of the seal I have: Attached Images

03-05-2018, 02:15 PM	#4
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,512	Re: Speedo Leak - Bullet Replaced That’s the one. I used a wood dowel to tap one into place. Put a little oil on the gear when you slide it thru. Helps keep the seal from burning out on first use. If it doesn’t stop the leak then you might need to replace the gear. They sometimes get a groove cut in them by that seal. Just a remote possibility of that.

03-05-2018, 02:27 PM	#5
cebra Registered User Join Date: Jan 2018 Location: Durham, North Carolina Posts: 782	Re: Speedo Leak - Bullet Replaced Excellent, thanks so much.

03-05-2018, 02:30 PM	#6
cebra Registered User Join Date: Jan 2018 Location: Durham, North Carolina Posts: 782	Re: Speedo Leak - Bullet Replaced Oh, just so I am sure, this is going in the back of the bullet (the threaded side) and the metal part of this seal is the part you tap in (the rubber going into the bullet)? Thanks.

03-06-2018, 02:45 PM	#12
ga-stepside Senior Member Join Date: Jan 2016 Location: Sugar Hill GA Posts: 368	Re: Speedo Leak - Bullet Replaced I got mine 2 years ago off EBay, worked perfect no leaks since. https://www.ebay.com/itm/TH350-TH350...QAAOSwMvtZVSOA __________________ 1967 C10 Step side 1970 AMX 390 1977 Datsun 280Z highly modified with '95 LT1 power

06-20-2018, 01:21 PM	#15
slikside Registered User Join Date: Jun 2010 Location: San Diego Co. Posts: 1,145	Re: Speedo Leak - Bullet Replaced Sub'd. __________________ 1972 Chevy C-10, SWB, Fleet, 350/350, PS, PB, all stock, Survivor.

06-20-2018, 03:36 PM	#16
67 chevelle Registered User Join Date: May 2013 Location: WEST PALM FLORIDA Posts: 1,174	Re: Speedo Leak - Bullet Replaced Sometimes the "driven gear" gets a grove in it on the skinny end , where the oring rides , if it does it needs replaced __________________ 68 Long Fleet , ly6 , turbo 350 , 3-5 drop , original paint , front discs 67 Small window , 7 foot bed , tweaked 6.0 LSX 2004R Medium Olive 58 Apache fleet , 235 , offy intake , dual exhaust , 4 on the floor , red/white 69 Long Fleet , Custom , 6.0, 4l60 , AC , Medium Olive

06-20-2018, 05:34 PM	#18
1969 Project Registered User Join Date: Sep 2016 Location: Brentwood CA Posts: 180	Re: Speedo Leak - Bullet Replaced I used a 9 tooth drive gear (green) and a 19 tooth Driven gear (natural) and my speedo is right on the money. The overall size of your tire also comes into play. You can get them at your local tranny shop or here http://www.laspeedometergear.com. He was pretty helpful when I spoke with him. Good luck!



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