6AT Torque Limits???

[oil_burner]

Does anybody have experience with transmission damage in their 35d? It seems that the official torque limit of the 6HP26 is 443 Lb/Ft, and most tunes would bring the trans past that limit. Does it require a tune or a complete rebuild to stay reliable? I'm not very experienced with transmissions, so any help is appreciated.

[yco]

it has different stages that can handle different torque figures like all transmissions..
and they all need disassembling for swapping for better seals and parts.. besides transmission lifespan is highly connected how you treat it though as you know.. assuming no faulty parts.. you can break a transmission by pulling on bad surfaces or putting too much load on it with the same power.. im used to nm not lbft but im guessing it should be around 600-650nm as you mentioned.. basically vibrations and another overlooked fact kills transmissions.. its the heat.. old fluids or below min level fluid can kill a transmission so fast.. seen many times with tuned cars, well maintained transmissions can handle more powers.. long story short for your question, yes it needs to be rebuilt..

[Spyro235]

Lots of us are deleted and tuned. 335d's and x5d's dyno on stock turbos with just deletes and tunes up to 550 ftlbs and you'll see people do that reliably for 100k+. As long as you're willing to change the fluid, filters, and some seals (not upgrade, just normal maintenance) the trans should last the life of the vehicle, even tuned.

There are people on hybrid turbos that push the limits and most all of them run stock trans. I'm not saying they'll last forever but this ZF6hp is a STOUT. trans.
Mine's at 257k miles, and it's been deleted and tuned for 45k miles. Ive also towed about 7k of those miles, maybe more than 7k at this point. And I'm not nice to it when towing, I kind of rip on the thing. Still fine, no real slipping, but the 4-5 shift misses if I'm absolutely full tilt and don't lift at all during it while towing.

But even that fault, no one but me would EVER notice that single particular fault in my beat on 256k mile transmission. As far as I know, I was the first person to ever service it, and that was at 230k miles.

[RL18]

Originally Posted by Spyro235

Lots of us are deleted and tuned. 335d's and x5d's dyno on stock turbos with just deletes and tunes up to 550 ftlbs and you'll see people do that reliably for 100k+. As long as you're willing to change the fluid, filters, and some seals (not upgrade, just normal maintenance) the trans should last the life of the vehicle, even tuned.

There are people on hybrid turbos that push the limits and most all of them run stock trans. I'm not saying they'll last forever but this ZF6hp is a STOUT. trans.
Mine's at 257k miles, and it's been deleted and tuned for 45k miles. Ive also towed about 7k of those miles, maybe more than 7k at this point. And I'm not nice to it when towing, I kind of rip on the thing. Still fine, no real slipping, but the 4-5 shift misses if I'm absolutely full tilt and don't lift at all during it while towing.

But even that fault, no one but me would EVER notice that single particular fault in my beat on 256k mile transmission. As far as I know, I was the first person to ever service it, and that was at 230k miles.

Santjer performance, when they ran nitrous w/ duel pumps and 100% injectors, had over 1,000 lb-ft of torque and about 670 hp to the wheels on their 335d running through a stock transmission... they ran a bunch of 1/4miles with slicks and their transmission seemed to take it fine.

All about how you treat it and maintain it.

[Spyro235]

Originally Posted by RL18

Santjer performance, when they ran nitrous w/ duel pumps and 100% injectors, had over 1,000 lb-ft of torque and about 670 hp to the wheels on their 335d running through a stock transmission... they ran a bunch of 1/4miles with slicks and their transmission seemed to take it fine.

All about how you treat it and maintain it.

Lots of guys running near those numbers on heavy nitrous shots too. I would love to have 700+ tq in my X5 on pump #2, but I just don't see the point in going for hybrids for the gains you get out fo them. If I could do it on injectors and maybe a dual pump (their bracket doesn't work on the X5) I'd heavily consider it.

But then again, if I need more power it's really because I'm towing more, and if I'm towing more it's probably time to just buy a real truck lol.

[RL18]

Originally Posted by Spyro235

Lots of guys running near those numbers on heavy nitrous shots too. I would love to have 700+ tq in my X5 on pump #2, but I just don't see the point in going for hybrids for the gains you get out fo them. If I could do it on injectors and maybe a dual pump (their bracket doesn't work on the X5) I'd heavily consider it.

But then again, if I need more power it's really because I'm towing more, and if I'm towing more it's probably time to just buy a real truck lol.

I hate that they don't work on our x5s cause I want dual pumps on my x5d not my 335d. But on stock everything (turbos, trans, stock injectors, etc) and only dual pumps, twin r90s, can support 425+ whp and probably close to 700 lb-ft. I could buy the kit for my 335d since I just upgraded to the r90 pumps and have the r70 sitting around for my second pump, but lots of $$$...

For our x5ds though we have the option to upgrade to the r90 pump. R90 will keep up everywhere, especially down low in rpm. One of the dyno threads showed an 80lb-ft increase in r70 vs r90 pump with same malone 2.9 tune. My x5d will be getting this pump. Definitely a worthwhile upgrade for the torque increase and to be able to keep steady rail pressure. R90 with hybrid Lp tims turbo upgrade should support 450+ hp and 700+ lb-ft though, which for $325 for r90 and around $1,600 for tims stage 3 lp turbo you're still less money than dual pumps at $325 for r90 and $2,300 for dual pump kits and you get similar power levels. Also, no need to upgrade injectors. Our stock injectors can keep up. I want to say they were good for something like 700hp, which is crazy.

Who needs a truck when you have an x5d with 700lb-ft

[Spyro235]

Originally Posted by RL18

I hate that they don't work on our x5s cause I want dual pumps on my x5d not my 335d. But on stock everything (turbos, trans, stock injectors, etc) and only dual pumps, twin r90s, can support 425+ whp and probably close to 700 lb-ft. I could buy the kit for my 335d since I just upgraded to the r90 pumps and have the r70 sitting around for my second pump, but lots of $$$...

For our x5ds though we have the option to upgrade to the r90 pump. R90 will keep up everywhere, especially down low in rpm. One of the dyno threads showed an 80lb-ft increase in r70 vs r90 pump with same malone 2.9 tune. My x5d will be getting this pump. Definitely a worthwhile upgrade for the torque increase and to be able to keep steady rail pressure. R90 with hybrid Lp tims turbo upgrade should support 450+ hp and 700+ lb-ft though, which for $325 for r90 and around $1,600 for tims stage 3 lp turbo you're still less money than dual pumps at $325 for r90 and $2,300 for dual pump kits and you get similar power levels. Also, no need to upgrade injectors. Our stock injectors can keep up. I want to say they were good for something like 700hp, which is crazy.

Who needs a truck when you have an x5d with 700lb-ft

That's awesome, about just the R90 upgrade. I really didn't know that the pump alone could net upgrades, is that with a tune oriented to it? I'd have to ask dudmd.

Thing is, my trans won't hold any more power in it's current state. My next big upgrade, after the new diffs/ new suspension, is going to be a trans rebuild or replacement along with sutphin's converter. I feel like I'd rather spend money at first on the converter before an LP turbo. The stock converter definitely leaves power on the table. Eventually, once I trust my trans, and have the upgraded converter, Id love to go for an LP.

When towing, I'm usually not full throttle. Trans doesn't really like it. Usually doesn't slip, but sometimes it does a tiny bit. Most of my towing is HP turbo spoolin.

[RL18]

Originally Posted by Spyro235

That's awesome, about just the R90 upgrade. I really didn't know that the pump alone could net upgrades, is that with a tune oriented to it? I'd have to ask dudmd.

Thing is, my trans won't hold any more power in it's current state. My next big upgrade, after the new diffs/ new suspension, is going to be a trans rebuild or replacement along with sutphin's converter. I feel like I'd rather spend money at first on the converter before an LP turbo. The stock converter definitely leaves power on the table. Eventually, once I trust my trans, and have the upgraded converter, Id love to go for an LP.

When towing, I'm usually not full throttle. Trans doesn't really like it. Usually doesn't slip, but sometimes it does a tiny bit. Most of my towing is HP turbo spoolin.

Yes the tune will optimize the r90 pump. I want to get my 335d back on the dyno and see the peak torque increase because at 2300-2500 rpm it pulls noticeably harder than before from down low and it feels like the torque doesn't drop off as fast as before too at peak power.

What suspension did you go with?

Is your trans tuned btw? I can't remember if I've asked you before

I can imagine the x5d doesn't like the LP spooling while towing but I'm wondering if it's your trans tuning. Which in my experience stock tuning translated to a sloppy shift while under load. What mode do you drive in while towing? D, DS, M mode?

If you do go with rebuilt trans with upgraded converter and tune you'll likely get better results. I'm sure your trans is tired!

[Spyro235]

Originally Posted by RL18

Y

What suspension did you go with?

Is your trans tuned btw? I can't remember if I've asked you before

I can imagine the x5d doesn't like the LP spooling while towing but I'm wondering if it's your trans tuning. Which in my experience stock tuning translated to a sloppy shift while under load. What mode do you drive in while towing? D, DS, M mode?

If you do go with rebuilt trans with upgraded converter and tune you'll likely get better results. I'm sure your trans is tired!

I'm basically going to replace every single component with new lemforder stuff. Arms, every bushings and ball joint, etc. It'll drive like a new car, hopefully. Love how these e70's look lowered, but I actually use every bit of my clearance sometimes, so I'm not going to be lowering it.
Mine is like, 80% of the time totally fine with spooling the LP while towing, but she hazes a bit from the extreme load. Trans isn't thrilled, but depending on the situation it's totally fine with it.

I'm tuned with sutphin's. I usually end up doing manual mode around city/town/ state roads, and if I'm using cruise control not he highway I'll put it in 6th. It'll hold 6th and roll into the boost in cruise, but it eagerly downshifts when in D sometimes. So on the highway for long distance I let it do load up gears on cruise control and if it starts losing steam it'll downshift. Around town I prefer M mode just to short shift it a bit, but if I leave it in D is really does do a fine job. When I towed for 2400 miles straight it definitely learned from it, and towed really nicely in D by the end of that trip.

If I go for a rebuilt trans I'm so tempted to do the whole package. Rebuild with upgraded clutches, sutphin's valve body, the converter, and I'll have a future proof transmission for the rest of my time with it. Realistically, if I ever get a new truck, I'll still have this and it'll become my girlfriend's daily driver. I'll still have the ability to use it to tow when needed if the bigger rig isn't necessary, and it makes a heck of a long haul vehicle. Especially after the future diff swap, it'll be a 32+ mpg long hauler with family capability.

[RL18]

Originally Posted by Spyro235

I'm basically going to replace every single component with new lemforder stuff. Arms, every bushings and ball joint, etc. It'll drive like a new car, hopefully. Love how these e70's look lowered, but I actually use every bit of my clearance sometimes, so I'm not going to be lowering it.
Mine is like, 80% of the time totally fine with spooling the LP while towing, but she hazes a bit from the extreme load. Trans isn't thrilled, but depending on the situation it's totally fine with it.

I'm tuned with sutphin's. I usually end up doing manual mode around city/town/ state roads, and if I'm using cruise control not he highway I'll put it in 6th. It'll hold 6th and roll into the boost in cruise, but it eagerly downshifts when in D sometimes. So on the highway for long distance I let it do load up gears on cruise control and if it starts losing steam it'll downshift. Around town I prefer M mode just to short shift it a bit, but if I leave it in D is really does do a fine job. When I towed for 2400 miles straight it definitely learned from it, and towed really nicely in D by the end of that trip.

If I go for a rebuilt trans I'm so tempted to do the whole package. Rebuild with upgraded clutches, sutphin's valve body, the converter, and I'll have a future proof transmission for the rest of my time with it. Realistically, if I ever get a new truck, I'll still have this and it'll become my girlfriend's daily driver. I'll still have the ability to use it to tow when needed if the bigger rig isn't necessary, and it makes a heck of a long haul vehicle. Especially after the future diff swap, it'll be a 32+ mpg long hauler with family capability.

Nice! Should definitely drive like new after! I know my 335d was like new when I rebuilt the suspension with all new m3 arms and did coilovers. You have the helper air bags in the rear too right? I'm not sure about lowering either... definitely looks okay stock. I'm gonna see how mine looks on stock then maybe do the bilstein b12 kit which isn't too aggressive but should look very nice.

Ah okay probably just a tired trans like you say. That trans should be stout enough to tow no problem. That's pretty impressive that it learns like that while towing though! My thought process on my x5d trans tuning is d-mode will be gf mode lol, ds-mode will be a tow haul mode, then m-mode configured for me.

I don't think I've heard anyone with an x5d with a trans rebuild. If you do go with it I'd love to hear your opinion on it! Should be the ultimate family hauler! I know my gf ask all the time to use my x5d and my 335d I'm just like don't you have your own brand new car lol. Shows you how nice these cars still drive for their age though