Basic transmission up-grades?

[Jim Ross]

We are now pulling a trailer that could weigh as much as 13,000 lbs when fully loaded and I am thinking that it would be wise to "beef up" the automatic trans on our 2007 (5. 9).

There is nothing wrong with the stock trans as far as I can tell (I use AMS/OIL ATF and service it regularly), but I'm thinking we are probably pushing its limits with this new trailer. The truck has 56K miles on it and no power upgrades other than the Smarty Jr.

What would most suggest as far as making the transmission better able to handle the load?

Valve body, shift kit, aftermarket torque converter... ... ? Other things?

 

[AH64ID]

A Torque converter and valve body would be a good investment.

Ultimate Transmission in Boise has a great reputation.

 

[LNaugle]

i would recommend suncoast. call john at suncoast 1-800-868-0053. then call shop in idaho for installation if they are close... .

 

[Jim Ross]

Good to know about the Boise shop. I tried to get registered on the Idaho Bombers site a few days ago and so far have not heard back..... I was hoping to find a local shop and not have to drive 500 miles.

 

[Jim Ross]

I have an email to Sun Coast, waiting to hear from them. I had their TC/Valve body, etc in my '01 and it worked very well.

 

[AWeaver]

I have all suncoast parts in my transmission. Running the smarty on 75% most of the time but occasionally will turn it all the way up. Both settings will break the tires loose on dry pavement. Haven't broke it yet. Only thing I dont like is that it does shift a litte firm for my liking but nothing too bad. My 01 was worse by far.

 

[Jim Ross]

From what info I am getting from local shops and here, it looks like a valve body with shift kit and a torque converter are on my horizon. One shop says a larger single disk tc will be enough, others are saying better to use a dual disk.
One shop says they would also go into the trans and put more clutches/plates (or something) in it as part of their total package. A new/different governor pressure solenoid has been mentioned by some.
I'm not a transmission guy, so I don't know exactly what they mean. Hopefully I can get better educated before spending money on something I don't need or won't like.
One of my dislikes with the stock trans/tc is how long it takes to get the trailer moving from a start. One shop told me that it will take even longer with an aftermarket tc because it locks up at lower rpm... ... . any thoughts on that?
My other dislike with the stock parts is the soft/mushy feeling, it just doesn't feel as tight to me as I think it should, but then I had the Sun Coast set up in my '01 and it was pretty firm---so maybe I got spoiled.

 

[cerberusiam]

A single disk TC should suffice for what you are doing. The upgraded single disks have about 20% more clutch surface than stock so with added pressures and a billet cover they work quite well. The triple disks can be problematicc unless the builder set sup the VB correctly and even in TH they will slam pretty hard. If you use a triple disk TC you WILL need a billet input shaft.

A TC that has a lowered stall and higher efficiency will accelerate the truck faster than the sloppy stock TC, given the stall is not so low the turbo will not spool correctly. These CR engines start defueling at 1800 rpms and by the time it is down to 1600 rpms they have dropped almost 50% of the fueling. Set a stall too low on a TC, load it down, and it will be a dog accelerating. Drop a Smarty on there with no added fuel and remove some of the TQ management and away it will go with less throttle than stock. A 1700 rpm flash stall, 2100 full brake stall, 85% efficiency converter should allow the stock setup to spool adequately and pull hard. A lot will depend on the converter construction and how they achieve stall and efficiency though.

The stock 48RE has 5 frictions in the direct clutch, 4 frictions in the forward clutch, 6 fricitons in the OD, 23 single sided frictions in the OD direct. In order to add clutches where they are needed in the direct, forward, and OD packs the clutches need to be thinner or maching needs done on the drums. Thinner clutches will NOT handle heat from towing as well. Machining new snap rings grooves can be problematic. A 48RE has more than adequate clutch capacity with pressure additions for your use.

A good shift kit, billet front servo, billet front band strut and anchor, billet accumulator, a good low stall billet cover TC added to the stock transmission will make a huge difference wihtout a huge investment.

If you want someone local give Chris Bowman in Mountian Home a call. He built mine and I have abused it with 450 HP/900 TQ and 21-23k loads for almost 100k without appreciable problems. The only issue is the crappy OE flex bad does not like high pressures and abuse. Highly reccommend a better band if you can swing it.

 

[Jim Ross]

Thank you, thank you!!!! Great info.
I have been back and forth with Muddy Thompson on the phone and with Rip at Source Auto by email.
This transmission thing is not something I have to do tomorrow, I have 6 weeks or more to get my money together PLUS deer and elk seasons are coming right up on us and since it takes a LONG time for me to get lucky enough to draw any tags, the hunts will take first priority.
I am very thankful for your info on NOT adding clutches... . Rip concurs, BTW.
Everyone seems to want to sell me multiple disk TC's and I really think a single will do the job OK. Not everyone agrees with buying an aftermarket Flex-plate, but to me, it is cheap insurance and the time to add it is when things are apart.
Your info was the best I have received from anyone, so thank you again.

 

[cerberusiam]

Tell Muddy Yo from me.

Flex plate is your choice. I am still running the stocker. When you get a billet cover on the TC there is a lot more contact area between the TC and flex plate. As long as the bolts stay tight it won't walk and flex like it does on the stock TC. Most of the failures are from the bolts loosening and the cover flexing under power and load, that gets eliminated with a billet cover. The rest of the failures are tearing the center out and that is just over powering it.

Its worth doing it when everything is apart, one less worry anyway.

 

[MUDDY]

allan. hey hey hey :cheer:

been seein ya here and wishin ya were back in ideeho... ... .

COME BACK!!!!!!!!!!!!

:THUMBUP:

 

[SDputter]

Not to highjack your thread Jim, but I have been wanting to know the same thing. I pull my 17K GVWR trailer regularly at around 14K+ lbs and have one hard pull on our regular camping trips. The wind is usually against us and the truck just won't pull 3rd up a grade out of the desert. When it drops to 2nd, I just wonder when the transmission will fall out of it, when the motor is singing a lullby at 3000 rpms. It seems if I had a little more torque, it would pull 3rd, and with the TC locked, the transmission would be happier and less likely to explode. Am I wishful thinking, or will chipping it to pull 3rd, just blow the transmission that much quicker? Or will an aftermarket TC like "cerberusiam" discribed above lock up in 2nd? Or will locking up in 2nd be harder on transmission? I've been doing it for 5 years now without a problem, but it just seems like a matter of time.....

 

[cerberusiam]

Am I wishful thinking, or will chipping it to pull 3rd, just blow the transmission that much quicker? Or will an aftermarket TC like "cerberusiam" discribed above lock up in 2nd? Or will locking up in 2nd be harder on transmission?

Both will make a huge differnece in how the truck pulls. With the TC unlocked in a hard pull a higher efficiency converter will transfer more power to the wheels. Added power in the form of a programmer will allow the engine to pull harder in the same rpm range and not downshift, you wil able to hold OD and drive locked a lot longer.

Unfortunately this will come at a price on a stock transmission. The extra TQ and power is going to hammer the TC clutch and direct clutches mercilessly. As little as 40 HP and 200 ft lbs of TQ will slip the TC under heavy throttle and destroy the direct clutch pack if you use the power. Stock pressures will NOT hold with extra power unless you are very easy on the throttle. If you add power you really need the shift kit and the easy upgrades. Pretty much the same if you add just a better TC. The TC will hold now the problem transfers to the direct clutches and with the extra power the good TC puts to the wheels your in the same position as adding power.

FYI, the stock transmission will lock the TC in 2nd gear IF you manually downshift to 2nd. It won't lock it fast and you will need to get the engine load under 50% or so to lcok but it will lock.

 

[SDputter]

I can't thank you enough cerberusiam for sharing, what I feel, is very good and easy to understand information, with inexperienced diesel and auto transmission people like me. I don't have any gauges, but the first reason for joining this site was to gain info on installing a transmission oil temp gauge. Like I said, I haven't had any problems yet. One last question if you dont mind... . If I manually downshift into 2nd, and get the TC to lock, and be a little light footed, will that lower transmission oil temps and not be too stressful on the direct clutches? I would think running the motor at 1600 rpms (loaded a little more) vs 2800 rpms (with TC unlocked) would be better for it.

Again, I appreciate all the info you have shared on this thread and others.

 

[cerberusiam]

I would think running the motor at 1600 rpms (loaded a little more) vs 2800 rpms (with TC unlocked) would be better for it.

LOL, this is where the discussion turns into efficiency vs saving the equipment. Discarding emtpy vehicle, lets talk about a heavily loaded vehicle.



At 1600 rpms it is way on the back side of the TQ curve. Yes I know the engine specs show a TQ peak at 1600 but that is not as installed in the chassis. As installed in the truck, the engine is heavy defuel mode an on the back side of the TQ curve. If you have much of any weight on it it is lugging. If you have a choice of lugging or running at 2800 rpms, 2800 is best for the motor and transmission. Not great for efficiency but thats the trade off. These engines are rated constant duty at 2800 rpms and 75% load so it is not bad for the engine, just the pocket book.



The second big thing is the effect the harmonics have on the transmission, and with an auto the fact the line pressures are so low. The harmonics hammer both the manual and auto hard under 1800 rpms, its the nature of the I6 engine. With an auto, line pressures are totally dependent on rpms and the stick pressures are so low at 1600 rpms there is enough TQ to slip clutches. If there was anymore TQ it would kill it fast. When you turn the power up and remove the TQ management on the engine WITHOUT addressing the transmission you find out quick just how fast the ISB can eat a transmission.



In 2nd gear the direct clutches are not on, they only apply in drive and OD. Second gear is the front band applied and running thru the front planetary for gear reduction. Leverage is better so the TQ rise has less effect on transmission, but, the crappy OE flex band has very little wear surface and is waeak with extended pressures. Hammer it hard enough often enough with the pressures up and it rips the ears off the band and there goes 2nd gear. Ask me how I know this...



Essentially any time you can get the TC locked you will lower trans temps, it is out of fluid coupling and routing more fluid to the coolers. If it is a choice of runnign higher rpms and locked TC by downshifting then that is always better than lugging it along in fluid coupling. Run it hard, the engine is built to take it.

 

[Jim Ross]

SD... no apology needed, you asked good questions and added to the quality of the thread.

Cerberusiam... . I'm working with Muddy (and he with Rip) to put together a parts list. I expect it will be early November before the work takes place. I'll "ease along" with the stock equipment until then. Your parts list is a huge help.

I did not mention it in my questions, but I do have a Smarty Jr. However, I don't think it is quite "right". I just can't feel much difference between running with it or running without it. I know others that swear by the Smarty, but maybe my Smarty or my truck is different. I've played with different settings for a couple of years and still not determined any big differences. Muddy says he can update mine when we get together in November or even try a brand new Smarty on my truck and see if there is any difference. I don't mean to start off on a different topic on this thread, just wanted to add the info.

Thanks to both of you for your info!

 

[NavyDood]

Ditch the Amsoil transmission fluid. You are wasting your money by using a boutique transmission fluid in our 48RE. Nothing more than a Chyrsler approved ATF+4 will ever be needed especially with the 48RE service interval.

http://www.centerforqa.com/licensedatf4brands.html

When my 5vr is fully loaded I am am 21k combined. My truck has 189,000 miles now. My Smarty Jr. is on the 70hp tune all the time unless I tow heavy and then I run the 40hp tune. I do 25,000 mile engine oil changes using Amsoil AME 15w-40, a single full flow oil filter (Donaldson ELF7349 or Amsoil EaO80) and no bypass. I change the transmission filter and refill every 30K-40K. I have no issues going 40K since I have the MagHytec DD pan. I have never touched my transmission bands and never will unless there is a problem directly related to them. I do all the above whether I tow or not. I don't go by the schedule "A"/schedule "B".

 

[cerberusiam]

I did not mention it in my questions, but I do have a Smarty Jr. However, I don't think it is quite "right". I just can't feel much difference between running with it or running without it.

You might just need an update and reload. It doesn't happen often but every once in a while you hear of somebody that says its not feeling right on the 06-07 trucks. Dunno why, their electronics ghosts I guess.

 

[SDputter]

No wonder the thing sounds good wound up!



cerberusiam, I'm curious how much money you have saved people?



Thanks again for all info!

 

[Jim Ross]

I will NOT ditch the AMS/OIL ATF... . it has done me great service in many trannys over decades. You use your stuff, I'll keep to mine.