Allison Transmission upgrade

[bjelder]

Here's the deal. Took truck in to have it scoped because I have recently been having the tranny go into limp mode last year three or four times throwing a Po735 code (5th gear ratio). When scanned it showed only that code. I was told the tranny needs to be overhauled, which I expected and saved to do anyway before final purchase on fifth wheel. Reason being my wife and I are going to be full time rv'ers pulling a fifth wheel which will weight between 15,000-15,500 lbs fully loaded and wanted to upgrade tranny before we start our venture. Truck is 2001 lb7 diesel one ton dually to bring you up to speed on that with the Allison transmission. My question is to do a rebuild or remanufactured replacement? Again other than possible the c2 and c3 disk likely burnt and not enough solenoid pressure to hold disc the tranny is awesome. There is no problem driving it daily, as code only throws when pulling my 17' aluminum boat and trailer up a hill which together doesn't even weigh 2000 lbs. Any advice on rebuild or remanufactered would help. Thanks in advance.

Jim

 

[HoytBows]

With the money you will have into it anyway, I would rebuild it with a suncoast kit and a new TC and the thing will be bullet proof and you will never have to worry about it again. Assuming you plan on keeping that truck for a long time.

 

[WarWagon]

You sure this 'old' truck is the platform you want to do full time RV touring/hauling with? My concern would be with the known troublesome injectors this year had. Also the head gaskets weren't that reliable on the first generation Duramax's.

You may want to run some numbers on trading up to a 2004LLY-2006 vs. cost of building a trans. I never had any transmission trouble with the Allison on my 2008 towing hot and hard. (No tune.) My 2005 has a killerbee trans tune that noticeably speeds up the shifts.

If you decide to keep it: I would rebuild your trans and replace/rebuild your TCC. Yours hasn't totally failed so it may be 'cleaner' than one that ate a lot of metal and then was rebuilt.

 

[saratoga]

Moved to Allison trans.

 

[bjelder]

You sure this 'old' truck is the platform you want to do full time RV touring/hauling with? My concern would be with the known troublesome injectors this year had. Also the head gaskets weren't that reliable on the first generation Duramax's.

You may want to run some numbers on trading up to a 2004LLY-2006 vs. cost of building a trans. I never had any transmission trouble with the Allison on my 2008 towing hot and hard. (No tune.) My 2005 has a killerbee trans tune that noticeably speeds up the shifts.

If you decide to keep it: I would rebuild your trans and replace/rebuild your TCC. Yours hasn't totally failed so it may be 'cleaner' than one that ate a lot of metal and then was rebuilt.

Although this "old" truck has issues, the injectors were all replaced before we bought it, maybe 100 yds. of travel. As for the head gasket issue, it to was resolved at same time. Truck came with cold intake filter along with upgraded exhaust. Also on it is the puck system trailer hitch, full length running boards w/ lights, heavy duty bumber hitch, and camper hitches only had 82,500 miles on it. Since purchase, 2 1/2 years ago have put diesel power additive in every time filled up. Also at end of 2012 added a secondary fuel filter (Donaldson filter w/ 2 micron) that has been change every other oil change. As with any vehicle nothing is 100% guarantee, the answer is to be as pro-active as possible as with the upgrade on the transmission BEFORE pulling a fifth wheel around. I truly do welcome your concerns, I just like the lb7 compared to the newer vehicles.

 

[THEFERMANATOR]

Don't let others scare you off, I still like my LB7. I prefer the LBZ, but the LB7 is 2nd, followed by the LMM, and then the LLY. The new style injectors are not that bad, and the LLY's are starting to have injector issues as well now. I'm going to assume you have a tuner on this truck, or somebody before you did as the ALLISON in stock form can run for a LONG time. Depending on what power level you want to run at would dictate which way to go with your build. If your staying stock and just want a slight bump in holding power, you can buy a TRANSTAR kit with RAYBESTOS clutches, install a TRANSGO HD2 shift kit, and a lockup boost valve along with the TRANSTAR billet cover converter and you can hold some decent power. A PPE stage IV kit is also a good kit for a basic truck. Just make sure you get somebody to build it who knows what they are doing, or buy from a vendor who can provide tech help during your build. The ALLISON isn't that hard to build, but it is VERY unforgiving if you make a mistake.

 

[bjelder]

Don't let others scare you off, I still like my LB7. I prefer the LBZ, but the LB7 is 2nd, followed by the LMM, and then the LLY. The new style injectors are not that bad, and the LLY's are starting to have injector issues as well now. I'm going to assume you have a tuner on this truck, or somebody before you did as the ALLISON in stock form can run for a LONG time. Depending on what power level you want to run at would dictate which way to go with your build. If your staying stock and just want a slight bump in holding power, you can buy a TRANSTAR kit with RAYBESTOS clutches, install a TRANSGO HD2 shift kit, and a lockup boost valve along with the TRANSTAR billet cover converter and you can hold some decent power. A PPE stage IV kit is also a good kit for a basic truck. Just make sure you get somebody to build it who knows what they are doing, or buy from a vendor who can provide tech help during your build. The ALLISON isn't that hard to build, but it is VERY unforgiving if you make a mistake.

If I want to add more HP/Torque what added items would I need. I was thinking of a re-manufactured engine with upgrades. But my tranny seems solid except for c2 and c3 likely burnt since I been throwing Po735 codes, so would a rebiult be better? Seems a remanufactured would be better as your relying on knowing a good allison tranny mechanic for a rebuild. Again this is only for heavy towing.

 

[THEFERMANATOR]

If I want to add more HP/Torque what added items would I need. I was thinking of a re-manufactured engine with upgrades. But my tranny seems solid except for c2 and c3 likely burnt since I been throwing Po735 codes, so would a rebiult be better? Seems a remanufactured would be better as your relying on knowing a good allison tranny mechanic for a rebuild. Again this is only for heavy towing.

To up the HP and torque a good tune, lift pump, exhaust, and an intake is all I would add. That is all I have on mine, and I never feel at a loss for HP. And also make sure your injectors AND CP3 pump are good. The high pressure CP3 pumps on 01-02 trucks is known to wear out around 150-200K miles and not produce good pressure(the 01-02 pumps start to get weak but still run good, 03+ pumps tend to just fail out of nowhere and leave you stranded but they do seem to last longer). I know I didn't have very good bottom end power out of mine, and I kept upping my tune to try and get more lower RPM power. Then it started to get hard to start and I found my CP3 was weak, changed it out and now it pulls like a mule down low. For your trans a good properly built trans by an experienced builder is always best. If you tell us where you're at we can probably recommend a good builder in your area. Depending on your goals a stock rebuild with a TRANSGO may be all you need, or you may want to step up to the PPE 4 with a triple disk converter. Whatever you do, DON'T SKIMP ON TRANS PARTS DURING A BUILD! Only go with known parts from a KNOWN vendor. Avoid shops selling cheap cut rate kits as well as many out there that have similar names to the known good ones as all they are doing is trying to deceive and get your money.

 

[Heartbeat Hauler]

I too have an '01 LB7 and I like it even though my injectors crapped out before 100K miles. But, I replaced them and still driving it.

Since you stated that you have an upgraded exhaust and air intake, I would rebuild the transmission (Sun Coast) and put in a triple disc torque convert (Sun Coast). For the boost in juice, I would stick with a 50 - 70 HP tune which brings along about 150 ft lbs of torque. My fiver was only 10K lbs loaded and this setup (trans is stock) let it stroll along at 70 mph without breathing hard no slip/limp. With the trans upgrade you could go to 100 HP easy which would move you and your 5ver quite nicely.

I would also consider synthetic fluids if you are gonna be pullin' 15K lbs full time. I would choose a synthetic brand that is readily available everywhere(!), i.e. Rotella 5w-40 for the Engine oil, Mobil 1 for the front/rear diffs. The trans is kinda tough finding synthetic readily available on your travels, but if you use something like Transynd you don't have to change it very often so being available may not be an issue.

Have fun and I am jealous!!! :thumbsup:

 

[bjelder]

To up the HP and torque a good tune, lift pump, exhaust, and an intake is all I would add. That is all I have on mine, and I never feel at a loss for HP. And also make sure your injectors AND CP3 pump are good. The high pressure CP3 pumps on 01-02 trucks is known to wear out around 150-200K miles and not produce good pressure(the 01-02 pumps start to get weak but still run good, 03+ pumps tend to just fail out of nowhere and leave you stranded but they do seem to last longer). I know I didn't have very good bottom end power out of mine, and I kept upping my tune to try and get more lower RPM power. Then it started to get hard to start and I found my CP3 was weak, changed it out and now it pulls like a mule down low. For your trans a good properly built trans by an experienced builder is always best. If you tell us where you're at we can probably recommend a good builder in your area. Depending on your goals a stock rebuild with a TRANSGO may be all you need, or you may want to step up to the PPE 4 with a triple disk converter. Whatever you do, DON'T SKIMP ON TRANS PARTS DURING A BUILD! Only go with known parts from a KNOWN vendor. Avoid shops selling cheap cut rate kits as well as many out there that have similar names to the known good ones as all they are doing is trying to deceive and get your money.

Thanks for your input. Greatly appreciated. I will do more research on what you and others have advised for needs in which I want to accomplish. Live in the Olympia, Washington area if you know of any good and reliable service shops in northwest. Again thanks.

Jim

 

[durallymax]

There is nothing wrong with the LB7, the LLYs have headgasket issues as well and as of late they have been going through injectors also. The new LB7 injectors have been holding up great.

If I want to add more HP/Torque what added items would I need. I was thinking of a re-manufactured engine with upgrades. But my tranny seems solid except for c2 and c3 likely burnt since I been throwing Po735 codes, so would a rebiult be better? Seems a remanufactured would be better as your relying on knowing a good allison tranny mechanic for a rebuild. Again this is only for heavy towing.

Reman is not better its a waste of money. You'll spend $4,500 out the door getting one put in. For that price you can pay someone to fully build your trans. If you want to see the socal area hook up the camper and head down to Inglewood transmission. Mike is great. I don't keep up with the new builders though that have shown up and maybe there is one in your area. Adrenaline truck performance in Idaho is great as well.

I too have an '01 LB7 and I like it even though my injectors crapped out before 100K miles. But, I replaced them and still driving it.

Since you stated that you have an upgraded exhaust and air intake, I would rebuild the transmission (Sun Coast) and put in a triple disc torque convert (Sun Coast). For the boost in juice, I would stick with a 50 - 70 HP tune which brings along about 150 ft lbs of torque. My fiver was only 10K lbs loaded and this setup (trans is stock) let it stroll along at 70 mph without breathing hard no slip/limp. With the trans upgrade you could go to 100 HP easy which would move you and your 5ver quite nicely.

I would also consider synthetic fluids if you are gonna be pullin' 15K lbs full time. I would choose a synthetic brand that is readily available everywhere(!), i.e. Rotella 5w-40 for the Engine oil, Mobil 1 for the front/rear diffs. The trans is kinda tough finding synthetic readily available on your travels, but if you use something like Transynd you don't have to change it very often so being available may not be an issue.

Have fun and I am jealous!!! :thumbsup:

I wouldn't run synthetic engine oil. There is no need to in the duramax, the oil filter fills up with junk before the Duramax fouls the oil. Easily run 10,000 miles on a good conventional oil. Our trucks get piss pounded around the farm and I run 10,000 mile intervals with Delo 400LE. UOAs look great and the oil is less than $12/gallon.

Synthetic ATF is okay for stock tranmisssions but with built ones its better to run cheap Dex III and change it every 30k.

 

[THEFERMANATOR]

I wouldn't run synthetic engine oil. There is no need to in the duramax, the oil filter fills up with junk before the Duramax fouls the oil. Easily run 10,000 miles on a good conventional oil. Our trucks get piss pounded around the farm and I run 10,000 mile intervals with Delo 400LE. UOAs look great and the oil is less than $12/gallon.

Synthetic ATF is okay for stock tranmisssions but with built ones its better to run cheap Dex III and change it every 30k.

There is one reason to run synthetic engine oil, I get faster cranking speeds with it. I can't fit two group 78's, so I run two group 75's and the cranking speed is a tad slow with them so I switched to 5W40 ROTELLA and it spins over a lot quicker. And from personal experience, QUATRASYN works best with ALTO clutches. I have run TRANSYND, DEX/MERC, and now QUATRASYN, and the QUATRASYN shifts the best of any of them(it also helped me to hit lockup in 3rd instead of 4th as it couples a tad better).

 

[durallymax]

Synthetic 5w40 is better for cranking and extreme temps but other than that its not gonna protect the engine any better and you arent going to get longer OCIs.

Now keep in mind, my opinion is based on managing our farms entire fleet so for me the overall costs are much larger than somebody only having to worry about one truck. Just buy using UOAs to help extend our drain intervals and by following the OEMs long intervals for warranty machines versus just changing every 200hrs like we used to I saved $9,500 per year. Switching to synthetic would not let me run anymore hours on our oil. Im already running 1500hrs or more on some machines. Most I still change annually though. Our two main semis sleep inside on cold nights becauae its just easier on everything. I use Delo 400LE 15w40. I run Delo 400XLE in our smaller diesels and in the semis for winter. A lot of fleets are switching to 10w30.

I do run synthetic gear lube in everything that requires 75W90 and 80W140 as well as synthetic 50w in our manual transmissions. I also run Chevrons HD Synthetic ATF in everything. I dont need to but I try to keep as few p r oducts on hand as possible since all of these get delivered 100 gallons at a time except the gear lube which comes in 16gallon kegs.

I also switch everything to Delo HD ELC coolant. I buy it premixed for $7.70/gallon. I never use Dexcool anymore. Delo HD ELC is rated for 8 years/15,000hrs/750,000 miles.

Our hydraulic oil is not synthetic. Go through far too much of that stuff to justify it. Chevron THF1000


Im not completely anti synthetic. It has its place thats for sure but for me im after a good value and simplicity. I dont want to micromanage our machines too much so if I can get away running similar products in all of them it makes life easier.

Sent from my SCH-R970 using Tapatalk 2

 

[swinters]

Interesting discussion, especially on synthetics. To me it's a classic "it depends" situation. There's a lot to take into consideration and sometimes synthetics are the best choice and sometimes not, depending on each situation. Oil is initially a certain base weight and then viscosity improvers, dispersants, anti-wear and anti-foam additives and so on are blended in. Different oil brands often use different additives to do the same thing, for instance some add copper as an anti-wear additive and that'll freak the lab if you're using oil analysis and don't tell them you've changed your brand of oil. Depending on the type of use, synthetics may provide better results. Oils biggest enemies are contamination and heat. The additives start breaking down immediately and the higher the heat the faster they break down. Synthetics tend to be blended with additives that tolerate higher heat (turbine engines use only synthetics) and they maintain their viscosity better and longer. Tests show that even in turbocharged engines that are cooled with engine coolant the turbo life is extended with synthetics. Extended oil change intervals are valid, but only if you use oil analysis. Oil analysis is trend based, so having samples checked on a regular basis is important so they can spot increases in wear metals, etc. and notify you of a pending failure well ahead of the event, so oil analysis not only save bucks in oil but also by keeping my repair costs way down. Whether to run synthetics depends a lot on what you do with your truck and if you work them hard, tow loads, don't idle your hot engine a bit before shutting it down and stuff like that then synthetics may be a good choice. Transmission fluid tends to follow the same rules. I use synthetics in my 07 GMC with the Duramax/Allison since I work it hard, and in the 6.2L engine of my Army CUCV since it has a Banks Sidewinder turbo. My 84 Suburban with the N/A 6.2L gets regular old "dinosaur squeezin's".

 

[THEFERMANATOR]

Interesting discussion, especially on synthetics. To me it's a classic "it depends" situation. There's a lot to take into consideration and sometimes synthetics are the best choice and sometimes not, depending on each situation. Oil is initially a certain base weight and then viscosity improvers, dispersants, anti-wear and anti-foam additives and so on are blended in. Different oil brands often use different additives to do the same thing, for instance some add copper as an anti-wear additive and that'll freak the lab if you're using oil analysis and don't tell them you've changed your brand of oil. Depending on the type of use, synthetics may provide better results. Oils biggest enemies are contamination and heat. The additives start breaking down immediately and the higher the heat the faster they break down. Synthetics tend to be blended with additives that tolerate higher heat (turbine engines use only synthetics) and they maintain their viscosity better and longer. Tests show that even in turbocharged engines that are cooled with engine coolant the turbo life is extended with synthetics. Extended oil change intervals are valid, but only if you use oil analysis. Oil analysis is trend based, so having samples checked on a regular basis is important so they can spot increases in wear metals, etc. and notify you of a pending failure well ahead of the event, so oil analysis not only save bucks in oil but also by keeping my repair costs way down. Whether to run synthetics depends a lot on what you do with your truck and if you work them hard, tow loads, don't idle your hot engine a bit before shutting it down and stuff like that then synthetics may be a good choice. Transmission fluid tends to follow the same rules. I use synthetics in my 07 GMC with the Duramax/Allison since I work it hard, and in the 6.2L engine of my Army CUCV since it has a Banks Sidewinder turbo. My 84 Suburban with the N/A 6.2L gets regular old "dinosaur squeezin's".

The key is to pick an oil that doesn't need additives and such to reach the desired viscosity, then you don't need the additives to maintain it. That is one of the reasons I switched to QUATRASYN in my trans as DEX/MERC fluid breaks down pretty quickly, but most synthetics don't bite like DEX/MERC fluid does.

 

[swinters]

The key is to pick an oil that doesn't need additives and such to reach the desired viscosity, then you don't need the additives to maintain it. That is one of the reasons I switched to QUATRASYN in my trans as DEX/MERC fluid breaks down pretty quickly, but most synthetics don't bite like DEX/MERC fluid does.

Yup - that's excellent stuff. I stay totally away from additives except for fuel additives. Danged ULSD...