Transmission / Smarty Questions

[MartyK]

Hello,





I would like to get my truck in the 500-550 horse power range. I also plan on purchasing a Smarty. I would like to do the transmission first, and one time. I have some questions in regards to building the transmission.

• What are some of the things that should be done or not be done?

• What happens to the tow/haul feature?

• Are there any negatives to a built transmission?



In some older threads people talked about their torque converters being 89% or 91%, what does this mean? I haven’t seen any resent post talking about this, does that mean is not applicable anymore?



From what I have read, the Smarty reduces the amount of pedal travel, but I thought the transmission builds fluid pressure based on pedal travel. Wouldn’t the reduced travel along with more power cause the clutches to slip even more?





Thanks,

Marty

 

[cerberusiam]

I would like to get my truck in the 500-550 horse power range. I also plan on purchasing a Smarty. I would like to do the transmission first, and one time. I have some questions in regards to building the transmission.

• What are some of the things that should be done or not be done?

TC, VB, billet input shaft if you want to play with a lockup controller

There any number if little tricks that go into building a trans if you

want to pay the bucks. Depends on how hard you want to play.



• What happens to the tow/haul feature?

It stays and works the same. That is an ECU controlled feature.



• Are there any negatives to a built transmission?

Only how sore your face gets from smiling :-laf



In some older threads people talked about their torque converters being 89% or 91%, what does this mean? I haven’t seen any resent post talking about this, does that mean is not applicable anymore?



Its still applicable. Its commonly referred to how tight the converter is or its efficiency. A stock converter is about 70% and converter made to harness a diesels TQ is in the 88-91% range. You will also want to look at the TQ multiplication along with the stall speed to match what you want to do and your setup. Best bet is call your vendor and tell them.





From what I have read, the Smarty reduces the amount of pedal travel, but I thought the transmission builds fluid pressure based on pedal travel. Wouldn’t the reduced travel along with more power cause the clutches to slip even more?



Yes it does, and yes it does. The pedal travel tells the ECU what to set governor pressure at. Smarty develops more power with less travel as reduce the TQ management. Truck feels great but unless you modify this behaviour it will eat your trans.



Thanks,

Marty[/QUOTE]

 

[MartyK]

"Truck feels great but unless you modify this behaviour it will eat your trans. "



Is this the case even with a built trans? Can the trans be modified to handle this and how?

 

[cerberusiam]

"Truck feels great but unless you modify this behaviour it will eat your trans. "



Is this the case even with a built trans? Can the trans be modified to handle this and how?

Not the case with an upgraded transmission. The answer was only in the context of Smartys removal of TQ management.



If you upgrade the trans with the above listed mods and a good builder that is familiar with the 48RE builds the transmission it will hold your power level without a problem.

 

[MartyK]

Cerberusiam, thanks for you help.

 

[RMalone]

You actually hit on my biggest Smarty gripe, transmission manners. Cerb is right, the lack of pedal position does cause some issues. The issues are noticeable even on a built trans. A built trans will handle it but on my truck the TC locks up completely different with Smarty as opposed to without Smarty. Without Smarty I will usually get lockup right at the 2-3 shift, or shortly thereafter. With Smarty it rarely locks in 3rd. Flair shifts are other thing I notice with Smarty but only at moderate throttle. All that said you just can't beat a Smarty for low end snap!!!

Marty I don't know where your at in Mi, but if you want to drive my truck to see what you think give me a PM. There is a very good trans guy in the Flint area also.

 

[cerberusiam]

You actually hit on my biggest Smarty gripe, transmission manners. Cerb is right, the lack of pedal position does cause some issues. The issues are noticeable even on a built trans. A built trans will handle it but on my truck the TC locks up completely different with Smarty as opposed to without Smarty. Without Smarty I will usually get lockup right at the 2-3 shift, or shortly thereafter. With Smarty it rarely locks in 3rd. Flair shifts are other thing I notice with Smarty but only at moderate throttle. All that said you just can't beat a Smarty for low end snap!!!

I am surprised you are seeing that type of reaction from a built trans. I added a DTT shift enhanser and then a Transgo shift kit and ALL the problems went away. No shuttle shift, no hang shift, even on Wild. I was impressed how the trans handled the Smarty power and what wild gave me.



Unfortunately, I lost a good drive engagement after 10k miles. We think either the direct clutch seals or the sealing rings on the pump hub are suffering. After almost 50k playing with Smarty on a stock trans I guess I should know better. Ah well, just an excuse for a TC and billet input.

 

[pwr2tow]

cerberusiam,
I'am thinking your problems went away due to the shift enhancer. It tricks the programming and raises the pressure with less throttle response. Alot (most) people with stock/modified engines and transmission don't realize the speed, rpm, transmission pressures have to be matched any time you change one parimeter so the rest will function properly. I know you know this but just pointing out to the others who might read this thread.

I've been thinking about putting one on my stock transmission and Smarty Jr. just to raise the pressures a little more with less throttle in an effort to help the transmission live longer. "Once bitten twice shy", on a transmission job from bd-power. Can I say "I took it up the _ _ _" on that one!!!!

 

[AClayton]

Can anybody install a shift enhancer or is best left to a transmission shop. I had mine tested for this very reason and was told,this is how it works... everything is OK. If the shift kit works,I'm willing to try it!

 

[cerberusiam]

cerberusiam,

I'am thinking your problems went away due to the shift enhancer. It tricks the programming and raises the pressure with less throttle response. Alot (most) people with stock/modified engines and transmission don't realize the speed, rpm, transmission pressures have to be matched any time you change one parimeter so the rest will function properly. I know you know this but just pointing out to the others who might read this thread.



I've been thinking about putting one on my stock transmission and Smarty Jr. just to raise the pressures a little more with less throttle in an effort to help the transmission live longer. "Once bitten twice shy", on a transmission job from bd-power. Can I say "I took it up the _ _ _" on that one!!!!

I cannot deny the shift enhancer is working. It does change my shift points when I change levels.



BTW, the shift points are still too high but I think it is because we used the heavier spring in the shift kit. Further talks with ttransgo indicate we should have used the stock spring in one place instead of what the kit said. It would be NICE if they put this info in their blasted instructions.



Surprisingly, I isolated the shift enhancer when the drive shifting problem started happening and the trans shifted pretty good without it. Once it goes back in am going to do the same and see if I can track exactly what it is doing. Since it was setup for a stock trans may have to send it in for programmming to new parameters though. Ah, well thats my spring project.

 

[cerberusiam]

Can anybody install a shift enhancer or is best left to a transmission shop. I had mine tested for this very reason and was told,this is how it works... everything is OK. If the shift kit works,I'm willing to try it!

The transgo instructions are pretty clear and relatively easy to follow. If you are used to doing this type of work it can be done.



I am paying somebody to do this becuase I don't have time to fix my own screwups. After watching it done, it would have been no big deal for but I do have a little experience working with the autos.



So far the transgo kit seems pretty promising. You get better pressures, took care of slipping the TC under power, no flare shifting, fluid flow in park. The only downside I have found is it is really easy to bark the turbo at partial throttle due to the aggressive lockup. WOT is not and issue but pushing 30-35 psi accelerating a load and you back out about the time the OD shift happens and the stocker will woof pretty good. :-laf

 

[LFarmer]

Can you give me the transgo part # or is it the only one available for the 48? Thanks

 

[pwr2tow]

I cannot deny the shift enhancer is working. It does change my shift points when I change levels.

BTW, the shift points are still too high but I think it is because we used the heavier spring in the shift kit. Further talks with ttransgo indicate we should have used the stock spring in one place instead of what the kit said. It would be NICE if they put this info in their blasted instructions.

Surprisingly, I isolated the shift enhancer when the drive shifting problem started happening and the trans shifted pretty good without it. Once it goes back in am going to do the same and see if I can track exactly what it is doing. Since it was setup for a stock trans may have to send it in for programmming to new parameters though. Ah, well thats my spring project.

Thanks for the info. So your saying even without the shift enhancer the transmission seems to work pretty good with just the valve body kit. That's good to know. My transmission performs flawless with the Jr and without so maybe I can get by with just a valve body kit. I've done mechanical work all my life, with the valve body kit do you need to remove some springs and balls then drill to enlarge a hole in the seperator plate? If I remember correct that's what we did back in the day.

I agree a heavier spring will make it shift firmer and later.

 

[MartyK]

Can you describe what a "Flair Shift" is? I sometimes get a quick shift, where it almost skips a gear. I wish it would hold a gear longer too.

 

[cerberusiam]

Thanks for the info. So your saying even without the shift enhancer the transmission seems to work pretty good with just the valve body kit. That's good to know. My transmission performs flawless with the Jr and without so maybe I can get by with just a valve body kit. I've done mechanical work all my life, with the valve body kit do you need to remove some springs and balls then drill to enlarge a hole in the seperator plate? If I remember correct that's what we did back in the day.



I agree a heavier spring will make it shift firmer and later.

Kit comes with a new seperator plate and different pieces from the earlier ones. IIRC, the drilling we did was on VB parts not the plate. This is a relatively new kit and replaces the one that fit all the OD , transmissions.



The instuctions list it as:



SK 48-RE

2003-2006 Diesel & V10

48-RE Application





There also a picture of the early and late VB's detail how to tell what kit to use. There is a vent that is only present on the 48-RE's. Everything else will use the SK TFOD kit.



DO NOT try to modify these instructions or add new features unless you are ABSOLUTELY sure what the effects will be. Early feed back indicates trying to add things like 1st gear lockup and other features gives very inconsistent results and possible trans damage. This kit is relatively new and aimed more towards a mild upgrade than fully built unit. They do things quite different than the older kit.

 

[cerberusiam]

Can you describe what a "Flair Shift" is? I sometimes get a quick shift, where it almost skips a gear. I wish it would hold a gear longer too.

When you get a noticeable rpm ramp up then drop during the shift, usually the 2-3 one. At light throttle and powered up the pressures are not high enough to get the shift to happen fast enough and engine will drive right thru the gear change. The 2-3 is the worst because it is a band release AND clutch apply. If there is not enoguh fluid and pressure to make them happen on time you get a cutaway between releasing the band and applying the direct clutches.



I am thinking this has contributed to my trans problems becuase I had it bad before the shift kit. After the shift kit 2nd and the 2-3 shift was very positive an tight. Everything was great except was bumping the rev limiter at every shift except OD. Keeping the shift points down around 2800-2900 would be much better for the TQ band I have. Trying a different spring and a tighter converter and see what the impact is.

 

[pwr2tow]

Everything was great except was bumping the rev limiter at every shift except OD. Keeping the shift points down around 2800-2900 would be much better for the TQ band I have. Trying a different spring and a tighter converter and see what the impact is.

Is it shifting at high RPM's on lite throttle, WOT, or towing?
If on lite throttle which spring are you referring too?

 

[cerberusiam]

Is it shifting at high RPM's on lite throttle, WOT, or towing?

If on lite throttle which spring are you referring too?

On WOT. The pressures are keeping the gears till that last iota is wrung out and the TQ is falling off. Thats how the stock programming is designed and the kit is meant to work for a V10 and diesel both.



According to Transgo, they would reccomend using the stock spring on what I believe is the pressure relief valve. This should help keep the gov pressure lower and allow an earlier shift point.



The part throttle shifts were great, anywhere from 1600 to 2600 depending on what I set the Enhanser at and how much throttle up to about 3/4. Over 3/4 throttle it tended to hold a lot longer before shifting. The Smarty helps a lot there as I have TQ to about 3200 before it starts dropping off but a shift a little lower especially with the closer ratios of the lower gears would help. OD shift was between 3000-3100 and it would drop to 2500-2600 which is about right.



With the OD shift happening between 75 and 80 I was running out of room most of the time to get a good feel for the acceleration in OD.

 

[pwr2tow]

On WOT. The pressures are keeping the gears till that last iota is wrung out and the TQ is falling off. Thats how the stock programming is designed and the kit is meant to work for a V10 and diesel both.

According to Transgo, they would reccomend using the stock spring on what I believe is the pressure relief valve. This should help keep the gov pressure lower and allow an earlier shift point.

The part throttle shifts were great, anywhere from 1600 to 2600 depending on what I set the Enhanser at and how much throttle up to about 3/4. Over 3/4 throttle it tended to hold a lot longer before shifting. The Smarty helps a lot there as I have TQ to about 3200 before it starts dropping off but a shift a little lower especially with the closer ratios of the lower gears would help. OD shift was between 3000-3100 and it would drop to 2500-2600 which is about right.

With the OD shift happening between 75 and 80 I was running out of room most of the time to get a good feel for the acceleration in OD.

Excellent post in describing what's happening. This is exactly what I'am looking for, 1600 RPM shifts for cruising and fuel economy, a little higher shift point around 2200 for towing (I take it easy towing usually just hold throttle or back off slightly to make shift), and maybe around 3000-3100 for get up and go purposes.

Stock spring would also lower other shift points, maybe I can talk to transgo and get a spring in between stock and what's normal in their kit. If not their spring sounds like it might do o. k. for my purposes.

Thanks again for the excellent description.

 

[cerberusiam]

Stock spring would also lower other shift points, maybe I can talk to transgo and get a spring in between stock and what's normal in their kit. If not their spring sounds like it might do o. k. for my purposes.

The springs are goping to lower shifts points across the board. They are not bad with the kit spring, but I want a little more fine tuning.



AFAIK, you have a choice between the kit spring and the stock spring, but maybe there is something they can come up with.