Bolt found in c6 tranny pan during fluid change.

5 oclock

Full Access Member
Joined
Feb 9, 2021
Posts
109
Reaction score
18
Location
Oregon
New to this. Curious if this has fallen out of something that could be effecting performance. That said, I am currently attempting to resolve a shifting issue between 1st and 2nd. It’s slow to shift and revving high to get there. Plan on goofing with the vrv as well. Really hoping I don’t have to put a new tranny in.
 

Attachments

  • image.jpg
    image.jpg
    355.2 KB · Views: 8
  • image.jpg
    image.jpg
    280.8 KB · Views: 8

XOLATEM

Registered User
Joined
May 5, 2023
Posts
355
Reaction score
401
Location
Virginia... in the brambles
Hey 5 oclock...

What I see that you have in your hand is a valve body bolt.

Is the pan still off the unit ? If so...take a picture of the valve body from directly below it and I can tell you where it came from.

You can let it sit for a while to stop dripping ATF of course...

Gotta resolve this issue before we can address the shifting problem.

Seeing that it is now 6:30 here on the East Coast...I could be an hour and a half late...sorry.

But wait...you are three hours behind me so I could be an hour and a half ahead of schedule...

All kidding aside...the torque on that bolt is not that much...can't remember what I used to put on them...but lets hope that the threads are not stripped.

Good luck, 5 oclock...
 

Rdnck84_03

Full Access Member
Joined
Jan 15, 2019
Posts
659
Reaction score
582
Location
Kansas
Definitely a valve body bolt, whoever rebuild trans last missed that one when they torqued them.

I found 3 of them backed out until they hit the pan when I disassembled the 4r100 in my wife's truck after I shattered the forward drum.

This is why I learned to do everything myself. That trans was built by a highly recommended builder in my area.

James
 

XOLATEM

Registered User
Joined
May 5, 2023
Posts
355
Reaction score
401
Location
Virginia... in the brambles
Definitely a valve body bolt, whoever rebuild trans last missed that one when they torqued them.

I found 3 of them backed out until they hit the pan when I disassembled the 4r100 in my wife's truck after I shattered the forward drum.

This is why I learned to do everything myself. That trans was built by a highly recommended builder in my area.

James
Hey Rdnck_03... did you figure out what caused the drum to shatter..?

I have seen that before and I figured that the unit must have gone to limp mode and then the resulting high line pressure would stress the drum when the driver put it in forward.
The outer edge where the top pressure plate and snap ring shattered away from the rest of the drum.
If the idle was high when it went in gear it would tend to make the drum flex there, also.

Also...just the fact that the drum is cast and then machined and not de-burred very well would tend to cause stess risers.

And...I would not put it past any bean counter to coax manufacturing to try to get away with a lower grade of cast iron if it was lighter and cheaper.
Just my .02
I used to have to select decent forward drums for C-4's from a pile to use in drag cars. Some were cheaply cast and others were close to cast steel. You just had to develop an eye for it.
 

Rdnck84_03

Full Access Member
Joined
Jan 15, 2019
Posts
659
Reaction score
582
Location
Kansas
@XOLATEM the drum shatter was a tuning/ heavy foot issue.

We bought the truck from a good friend of mine which had just had the transmission rebuilt a few hundred miles earlier. Shortly after buying it I installed a php hydra chip. I asked him if he had a modified valve body installed when he had it rebuilt, which he told me that he didn't. I installed the tunes for a stock valve body.

Fast forward about 6 months. I pulled out of a parking lot and noticed the long winded stoplight down the street was green so I floor it trying to make it and it down shifted to first, sounded like a shotgun went off under the truck.

Had my buddy I bought it from tow it to my shop, tore the trans down to find three valve body bolts backed out, the center support bearing non existent, and the forward drum shattered. Also found a transgo tugger hd2 installed in the valve body.

So I blame the failure on the center support bearing failure and the fact that the line pressure was way too high with the shift kit running on tuning for a stock valve body.

Only thing I did was replace the forward drum with a cheapo from ebay, center support bearing, install tunes for the modified valve body. Have put about 95k on it since with no more issues.

James
 

XOLATEM

Registered User
Joined
May 5, 2023
Posts
355
Reaction score
401
Location
Virginia... in the brambles
---sounded like a shotgun went off under the truck.---
Do you remember your first reaction when you heard the 'boom'..?

It's times like that that surprise me with the first thing that I think...or what comes outta my mouth...

Sometimes it's comical and sometimes ...not....

I'm wondering how that bearing failed...I have never seen them fail...you are talking about the captured bearing between the drum and support...at the base of the ring tower..?

I imagine if the back-end geartrain clearance was set up too tight then that would wipe the bearing.
 

Rdnck84_03

Full Access Member
Joined
Jan 15, 2019
Posts
659
Reaction score
582
Location
Kansas
Considering how long it took me to find the bearing I am betting it wasn't replaced during the rebuild. For some reason that bearing seems to be an obsolete size. I bought the only 5 of them I could find listed on ebay. 3 of them were skf and I don't remember the brand of the other 2 .

I will take the stoplight any day over a f'ing roundabout.

James
 

Old Goat

Full Access Member
Joined
Jan 14, 2021
Posts
1,239
Reaction score
1,035
Location
Northern Nevada
That's it...we need to do away with stoplights...make 'em all traffic circles...

That'll stop a lot of transmission failures...
Soap out your mouth talking like that.
They are putting them all over Nevada.
No one know`s what Yield means.

Actually they say they are traffic calming.
S C R E W it, punch it, beat the light.


Goat
 

XOLATEM

Registered User
Joined
May 5, 2023
Posts
355
Reaction score
401
Location
Virginia... in the brambles
Considering how long it took me to find the bearing I am betting it wasn't replaced during the rebuild. For some reason that bearing seems to be an obsolete size. I bought the only 5 of them I could find listed on ebay. 3 of them were skf and I don't remember the brand of the other 2 .

I will take the stoplight any day over a f'ing roundabout.

James
I'd trust the SKF before other off-shore brands...I believe Torrington invented them. they get full of contaminants from a previous failure and are hard to clean and inspect without destroying them. I don't know about now...with all of the supposed supply-chain issues...it has been years since I bought any...don't know how available they are.

I was overseas once and driving in a roundabout and the car next to me...I could almost reach out and touch the other driver...talk about nerve-racking...
 

5 oclock

Full Access Member
Joined
Feb 9, 2021
Posts
109
Reaction score
18
Location
Oregon
K... after more digging you are right X. Filter bolt. Hole is stripped. Last knucklehead cranked it to hard..probably got it to stay, and then it fell. Thankfully that magnet caught it.

Called a transmission shop today to get a new tranny put in I had sitting here. I don't have the time. Come to find out neither does he. Doesn't have enough help to even do the work. Anyway... my only option is to just leave the one bolt out, torque the others to the proper spec (I read 60 in lb) and then fill her back up. Unless anyone has a better idea?

Once filled I am going to mess with the VRV I have also ordered the mechanical conversion from accurate if the VRV is bad.
 
Last edited:

5 oclock

Full Access Member
Joined
Feb 9, 2021
Posts
109
Reaction score
18
Location
Oregon
Also decent amount of silver sand in the pan along with 1 pin head sized piece of metal. Magnet was presumably maxed out coated in metal. The added realization of these two findings is what prompted me to assume this thing may have been 1. overfilled for a while (my fault, didn't take the time to drain it) 2. Not being adequately filtered. 3. Hard shifting first and second (Went from a noticeable shift within the margins to now not wanting to shift at all from 1st to 2nd most of the time). Now suffering as a result
 
Last edited:

XOLATEM

Registered User
Joined
May 5, 2023
Posts
355
Reaction score
401
Location
Virginia... in the brambles
At this point it does not sound promising to me...especially with the 'silver sand'... If I remember correctly...one filter bolt is longer than the others and it is easy to overlook that and put a short bolt in the long hole.

I have a feeling that you are prolonging the inevitable...but that is just me...I would yank it out and rebuild it if it were mine...and probably replace the flexplate and check the pilot hole in the crank for oblong wear. 'silver sand' could be pump or torque convertor metal or some other problem that is just going to wear out more parts.

The particles you are describing have a way of jamming up the valves in the valve body and the governor on the output shaft. that is going to cause the shifting problems. The valve body and governor castings are aluminum...sensitive to contamination.

While we are on the subject of contaminants...whatever you do...you gotta flush adequately the cooler and cooler lines...or you are going to have continuing, maddening, depressing misery with this thing.

Just 'blowing them out' with air or such is just not going to cut it. You have to FLUSH and BACKFLUSH the cooler and lines to give your new or newer trans a fighting chance to work right.

Good luck on it...
 
Top