Notices
Modular V10 (6.8l)  
Sponsored by:
Sponsored by:

Transmission question for the guys that know

 
  #46  
Old 04-13-2019, 12:23 AM
Mark Kovalsky's Avatar
Mark Kovalsky
Mark Kovalsky is offline
Post Fiend
Join Date: Aug 1999
Location: SE Florida
Posts: 18,171
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
The torque converter is NOT the pump. The torque converter mates to the pump, which is inside the transmission. The pump supplies pressure to the entire transmission including the torque converter.
 
  #47  
Old 04-13-2019, 01:05 AM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
The motor bolts to torque converter. Torque spins the fluid to the pump and then pump supplies fluid to the whole transmission so if the return from cooler was to be unrestricted would it be better for the torque to have more fluid so as to eliminate bottleneck and have full flow or should it have a restriction to limit the amount of pressure to clutches or bands ??? When I work on hydraulics they tell me the less restrictions the better off you'll be. Pressure takes the path of least resistance. I know this isn't a hydraulic pump as I know it could you tell me if there is a flow rate from torque to pump that I can understand and is there a pressure relief valve or something of the sort. In an 4r100 that can limit pressure ??? Is that what the valve body is for??? Sorry for all the questions but just trying to understand what makes a transmission so complicated. It kind of reminds me of a automated digger. The more pressure that's given the digger the harder and more efficient it works but if given to much the internals wear faster and then leads to a failure. So I'm just looking to understand the fine line between efficient and failure in a transmission. And thank you for taking time to teach me.
 
  #48  
Old 04-13-2019, 09:39 AM
Mark Kovalsky's Avatar
Mark Kovalsky
Mark Kovalsky is offline
Post Fiend
Join Date: Aug 1999
Location: SE Florida
Posts: 18,171
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
Fluid does not flow from the torque converter to the pump. The flow rate in this direction is exactly zero.

The pump sucks fluid through the internal filter from the pan. It sends the pressure to the main regulator valve, which controls line pressure. All pressures in the transmission are fed from line pressure.

The torque converter is fed through the torque converter limit valve. This valve limits torque converter pressure to 120 PSI. If the converter gets much more than that it will inflate like a balloon and be deformed. Flow out of the torque converter is sent to the coolers. From the coolers, it is sent to the lube system that lubes the rear of the transmission.

I don't know what will happen if you remove the restriction that you see in the banjo bolt. If it flows much more than stock I can speculate on a couple things that could happen:

1. Faster flow through the coolers could result in lower heat transfer and a warmer transmission. There has to be some dwell time in the coolers to get heat transfer.
2. The torque converter pressure may be lowered. The torque converter limit valve will keep trying to maintain 120 PSI. This will draw more flow from line pressure. If the pump can't keep up with that demand ALL pressure is cut from the torque converter. This is done to protect the clutches in the transmission. The result of that is the torque converter clutch will not apply, you'll lose 3-4 MPG, and the transmission will get HOT.

There is a lot of work done on all transmissions to balance all of this. If you don't have an extensive test program with several instrumented transmissions to analyze what's going on with the flow I expect that you will not improve the system.
 
  #49  
Old 04-13-2019, 12:29 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
Thank you for clearing me up on this I appreciate that. As far as bottle necking at the banjo bolt I was told that there is a fitting sold that eliminates this choke point and that it restricts a lot of fluid. I will try to post a link to it if I can figure out how but they make it sound very convencing. But if you say that it's best to leave it alone then that's what I'll do. I'll get that link to you In a bit. Thanks again
 
  #50  
Old 04-13-2019, 12:33 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
  #51  
Old 04-13-2019, 12:37 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
  #52  
Old 04-13-2019, 02:50 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
These are two sites that the other transmission repair guy told me to check out they sound convincing but I'd rather have my knowledge from an expert if yousay it wouldn't be a good idea then that's what I'll do. But read the links and tell me what you think
 
  #53  
Old 04-13-2019, 04:28 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
  #54  
Old 04-13-2019, 04:29 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
  #55  
Old 04-13-2019, 04:31 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
Read these Mark and tell me what you think. I would appreciate your opinion on these links. Thank you
 
  #56  
Old 04-14-2019, 10:48 AM
Mark Kovalsky's Avatar
Mark Kovalsky
Mark Kovalsky is offline
Post Fiend
Join Date: Aug 1999
Location: SE Florida
Posts: 18,171
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
Both of those are about removing the bypass. I do not think that is a good idea.

It is true that the bypass spring can get weak or fail, allowing fluid to bypass the cooler. If you have a trans temp gauge (and there is one on the dash that contrary to popular opinion really does work) you'll notice the trans temperature rise. Now you've recognized you have a problem and can fix it. A rebuild kit for the bypass is about $25 and is really easy to install.

If you don't have a bypass and something happens that restricts the flow through the coolers your first indication that something is wrong is that the transmission fails due to lack of lube flow. That will be a catastrophic failure, meaning you're going to have to replace a lot of hard parts for a lot of money.

The bypass removal solves a very minor problem with a very major risk. I don't think it's a good idea.
 
  #57  
Old 04-14-2019, 01:10 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
If I leave the bypass line in and just remove the banjo bolt spring and ball. If I have a cooler failure would the bypass line still work to provide fluid to rear of transmission. If I leave the bypass tube ball and spring alone and just remove the bolt spring and ball. Would that solve any bottle necking or just cause more problems??
 
  #58  
Old 04-14-2019, 04:08 PM
Mark Kovalsky's Avatar
Mark Kovalsky
Mark Kovalsky is offline
Post Fiend
Join Date: Aug 1999
Location: SE Florida
Posts: 18,171
Mark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputationMark Kovalsky has a superb reputation
I thought we just covered this. Are we starting over?
 
  #59  
Old 04-14-2019, 04:33 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
I thought we've talked about removing the bypass tube and the banjo spring and ball together. I didn't realize that we covered just removing the spring and bolt from just the banjo bolt by it's self and leaving the bypass tube.
 
  #60  
Old 04-29-2019, 11:01 PM
wickerbill
wickerbill is offline
Junior User
Thread Starter
Join Date: Mar 2019
Location: LEWIS CO. WV
Posts: 65
wickerbill is starting off with a positive reputation.
I put the knew trans heat gauge in before I put the new tube on and it said it was between 140 and 150 degrees. The truck is empty with no load. And that was with around 6o miles on it with a few stops and a drive through for food it seems like it's ok but what temp should it run at on a 75 degree day
 

Thread Tools
Search this Thread

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.