Author Topic: Transmission issues  (Read 4192 times)

Offline Stewart G Griffin

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Transmission issues
« on: July 23, 2017, 10:13:01 PM »
How ironic---i finally got around to becoming a site supporter and now i have to park the truck;  Pls see my upcoming post concerning the transmission.

i got my eyes on:  Chevy SS, tahoe, newer (2007 and up) silverado, colorado

It's definitely fixable, but i just don't have the time.

Offline fitz

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Re: Transmission issues
« Reply #1 on: July 24, 2017, 06:55:49 PM »
Stewart, 
Doesn't your truck have a turbo 350 trans?
You can get a B&M or TCI trans from Summit/Jegs for about $1,000.
A Saturdays worth of work on the truck and your back on the road

Offline Stewart G Griffin

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Re: Transmission issues
« Reply #2 on: July 26, 2017, 10:59:29 PM »
Stewart, 
Doesn't your truck have a turbo 350 trans?
You can get a B&M or TCI trans from Summit/Jegs for about $1,000.
A Saturdays worth of work on the truck and your back on the road

i'm thinking of doing just that.  Will discuss fully in an upcoming thread.

Offline Irish_Alley

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Re: Transmission issues
« Reply #3 on: July 27, 2017, 12:24:29 AM »
stew i know you know maryland, you live on the western shore? what tail shaft is on you th350? i think my buddy has one that i know is good cause we pulled it out of my 86 a few years ago. but want to say it had the 6"
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Offline Stewart G Griffin

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Re: Transmission issues
« Reply #4 on: July 27, 2017, 09:59:36 PM »
Thanks for the offer;  You would think 9", but i'll check soon.

Will discuss in greater detail this weekend.

Offline fitz

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Re: Transmission issues
« Reply #5 on: July 28, 2017, 03:54:33 AM »
You could always run a 6" tail shaft trans and have your driveshaft modified to fit it.

Offline Stewart G Griffin

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Re: Transmission issues
« Reply #6 on: July 30, 2017, 06:44:35 PM »
Just checked---it's a 9".

Thanks for the offer.  i think i want to go rebuilt anyways---IF i even need to replace;  Will describe the situation in more detail in another thread.

Offline Irish_Alley

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Re: Transmission issues
« Reply #7 on: July 30, 2017, 09:42:32 PM »
better yet stew look for a 700r4 with the correct driveshaft. getting one rebuilt might cost 400 or so (never priced a th350) and you can buy a used 700r4 for about the same price and get OD to help with your MPG
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Stewart G Griffin

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Re: Transmission issues
« Reply #8 on: July 30, 2017, 11:54:57 PM »
i know i'm getting off topic here, but crawling under the truck today made me again wonder why i have a 1-pc driveshaft and yet other 1/2 ton longbeds have a 2-pc shaft.  i think it has to do with rpm---a longer shaft can't spin at high rpm as well as a 2-pc---due to flex.   i have 2.56 gears and thus it's ok.  But a truck with 3.73-4.11 probably wouldn't work so well.
« Last Edit: July 31, 2017, 12:07:17 AM by Stewart G Griffin »

Offline Irish_Alley

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Re: Transmission issues
« Reply #9 on: July 31, 2017, 09:34:25 AM »
I split the topic so we're not hijacking it. It kind of makes sense about the 1 piece vs 2 with the rear ratio. Maybe after a certain ratio they have to use 2 piece
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Offline Stewart G Griffin

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Re: Transmission issues
« Reply #10 on: July 31, 2017, 12:29:52 PM »
We should probably transfer this to the driveline section, anyways:

Here is my touchy situation:


1) It all started as i was in the process of flushing the cooling system----this took about a week as i really wanted to get it clean---so i drove with the prestone super flush for about a week.

2) Last Satudray,  Upon draining and refilling with water, i discovered one of the trans cooler lines leaking--- lots of water onto the front crossmember.  i originally thought it was the lower radiator hose, but no, it's the line on the bottom, closest to the tie rod, which is i believe, the outlet/  trans-to-radiator line?





3) i do not know how long water has been getting into the trans or if it HAS been getting into the trans?   But apparently the trans cooler is leaking?  i believe the trans line leak is recent, but have no idea how long the trans cooler has been leaking.

4) But the trans still seems to work just fine.

5) So, i'm thinking, since the trans is 34 years old and could probably use a freshening up/replacement anyways. (never been rebuilt as far as i know)  IF i were to just change the fluid/flush the transmission (could use one of these as well), then if i keep driving it, then i wouldn't really mess it up anymore, if in fact the transmission is already screwed?

6) If the transmission, IS NOT hosed, then i should just keep driving it after flushing and changing fluid?

What do you think is the best course of action?

Offline Rattler12

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Re: Transmission issues
« Reply #11 on: July 31, 2017, 05:35:06 PM »
Aren't trans lines to trans coolers  supposed to have trans fluid in them  and not water?
83 C-10 shorty 454, 5spd, 3:73 posi

Offline Stewart G Griffin

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Re: Transmission issues
« Reply #12 on: July 31, 2017, 06:41:55 PM »
Aren't trans lines to trans coolers  supposed to have trans fluid in them  and not water?

Exactly.  What i'm thinking happened, or might have happened is that the trans cooler in the radiator is leaking.

Offline Irish_Alley

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Re: Transmission issues
« Reply #13 on: August 01, 2017, 10:22:22 AM »
water and trans fluid is just like oil and water. they wont mix but turn milky red (with the trans) how the fluid look in the trans? you have n signs of trans fluid in the rad?
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Offline Stewart G Griffin

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Re: Transmission issues
« Reply #14 on: September 23, 2017, 11:17:39 AM »
UPDATE: 9/23

Back around jul 31st, i had parked the truck and had a other unrelated life issues to deal with.

i took it for a test drive last night and again today and there were absolutely no signs of leakage whatsover----water or ATF.

The only thing i did, was around July 29th or around the last week of July, i had replaced the lower radiator hose-----because i thought this was the culprit of the leaking.  The area of the leaking seemed to coincide with the area around the white UPC sticker.   However, even with the new hose, there was still signs of leakage, leading me to believe it was the trans line since water was coming off the trans line in both cases with both radiator hoses.   Note that the lower radiator hose and the lower trans line are and were in contact for over 1 year and still are.   (yes, i know i need to take care of this)   This is when i decided to park the truck and deal with it when there was more time.

i am currently testing the old hose----by filling with water and positioning both ends upwards so that water does not come out.    There does not appear to be any leakage.  Granted, this test is with the hose off the engine, so:

1) Which hose is under pressure when the engine is running----the lower, the upper, or both?


2) If there is no leakage from either of the transmission cooler lines OR from the lower radiator hose or other coolant hoses.   And there does not appear to be any now, then where do you think the water came from?


The only things i'm coming up with is the outlet from the coolant overflow tank;   Since i was in the process of flushing the radiator, i had, perhaps, been "overzealous" in filling the system to the brim---in hopes of doing a thorough job.   Thus, excess water MAY have come out of the overflow spout.  However, the overflow spout is no-where near where the water would get onto the lower trans cooling line.

The other thing is i MAY have forgotten to close the radiator cap completely----because this was a repetitive process of the filling, draining, filling etc.   i can't say there is a high likelyhood of this, but it's possible.











Not the greatest pics, but the fluid does not appear to be Pepto-Bismal or strawberry milkshake.  Trans seems to shift fine.  Fluid level seemed normal.