Engine/Transmission (1998.5 - 2002) Exhaust Brake on Automatic

[PurdellMGP]

I have been thinking about an Exhaust Brake, but my problem is I have an automatic transmission. I have read how you should not put one on your truck unless it is a standard. How can this exhaust brake ruin an automatic? Or is this a myth? If it is only putting back pressure on the exhaust, how can that effect an automatic?



Thanks for the help in clearing this up.

 

[old4wheeler]

As I understand it - when you let off on the throttle to apply the exhaust brake, the internal transmission pressures drop. The decrease in transmission pressure will allow the torque converter lockup to slip - not good for the converter.



old4wheeler

 

[Heetseeker_1]

You will get several good expanations about the internal problems with the brake on your trans but the bottom line is... you will smoke the trans if you run a brake on it if the trans is not modified with beefy parts. DTT did my mods on the old trucks trans and it really hooked up the power better as well as modified it for using the brake. The mods can be expensive, but they are the foundation for bombing on an auto truck.

 

[BarryG]

MPurdell:

Heetseeker wrote the bottom line effects. If you go to

http://www.dieseltrans.com/phpBB/viewtopic.php?t=6

it is a good writeup on exhaust brakes with an auto trans that explains the issues and how to overcome them. Now that is one of the well known trans rebuilders websites and whether you use them to upgrade the trans or not is up to you as others can do it as well but they do have a good write up on it.

 

[jtwcummins]

Not going to say one way or the other, but I have been running EB for almost 3 years. It's on all the time and transmission is stock 47re. Has a Smart Lock that controls TC lockup and increases line pressure when on.



I do get trans serviced regulary

 

[LKothe]

Where can I get more info on the Smart Loc. Does it also "unlock" the TC lockup?



Thanks, Goldmaker

 

[KTobin]

Here's a link to the setup I have with my 2002 auto. I run a BD brake with "autoloc" and a "Pressureloc" transmission kit. It's a nice set up and it works well for me. I've seen used "pressureloc" trans kits going on EBAY for as little as $60. They're a simple vacuum actuator with not much to go wrong with them. Hope this helps.



http://www.dieselpage.com/bdebd.htm



Kevin

 

[jtwcummins]

Most aftermarket Ebrakes have a black box control for the auto. It includes the pressure lock, this is a vauum controlled valve that increases line pressure when brake is active. On the Banks, and most others, when the truck is started it turns on the EB to aid warmup. Touching the accelerator disengages during warmup and when stopped it turns it back on until temp gets to about 140. Acts like the heat riser in gasers. When the brake is being used the TC is locked until speed reduces to 22 mph with OD on and 18 w/OD off.

The black box connects to ECM wiring. TPS, ECT, VSS and OD switches are connected.

The pressure lock mounts on the trans on the drivers side. The throttle cable is removed and the unit mounted, then the cable is reconnected. the 47re has very low line pressure at idle and increases with throttle movement. The pressure lock forces the pressure to full on during operation of the EB.



The only thing is if you use the truck brakes to stop quickly the unlock process and the down shift happen at almost the same time. This can be felt as the trans can't react fast enough to unlock and shift at the same time. This happens during panic stops and hasen't hurt anything yet.

I run the EB all the time. It's nice coming to a freeway offramp and having the truck slow when off the gas. Really saves the trucks brakes. Since braking is not very effective below 2k rpm in town it's not as effective.