Driveshaft upgrade?

480Ruger · October 1, 2014

Hello everyone,

I stopped by a well known performance shop Monday to set up a time to dyno the truck and have it tuned. They said they would only street tune it but couldn’t run it on the dyno unless I upgraded the driveshaft. This is the first I’ve heard of this. I’m wondering if they just had a bad experience.

I had over 742 hp and 1307 tq on my old dodge Cummins and never had an issue with the driveshaft after years of drag racing and sled pulling. I broke about everything else though.

Anyone else have any issues? 2014 6.2L 4x4 CC standard bed stock 20” with only upgraded CAI and exhaust.

Thanks,

Gregg

Chris · October 1, 2014

My 04 was dyno tuned with stock 2 piece steel driveshaft

white1500 · October 1, 2014

If you fall for it they might do the job.... $$$$ for them. They might even say you need new tires and a steering coupler for good measure.

MikeNH · October 1, 2014

Seen a few trucks spit out driveshafts on dynos in videos. Figured it's ones that bypass the speed limiter and then let go.

Prokopchuk_9 · October 2, 2014

Seen a few trucks spit out driveshafts on dynos in videos. Figured it's ones that bypass the speed limiter and then let go.

Or running 400-600 shot of nitrous when it's already making 1800+ ft-lbs LOL...that could have something to do with it.

They sound like a bunch of crooks, you don't need new shafts

TJay74 · October 2, 2014

I know Alvin at PCM4less wont dyno tune them. He said they had one come apart on the dyno and don't want to take the chance again.

CorvetteOJ · October 2, 2014

TJay is 100% correct. I have had three three trucks dynoed by Alvin, a Hummer H3, '12 Silverado, and my current '14 Denali 6.2L. He will not put a truck on the dyno, although he owns one of the best I have ever seen. He also told me he had one truck's drive shaft come apart once and messed up the truck and his dyno. I have been happy with all my tunes from Alvin, although I am considering getting a spot on Blackbear's next available tuning session to see if there is any noticeable difference. My current PCM for Less tune is 10 months old and seems like it has lost something. It may just be my imagination, but I am curious, since Blackbear evidently has a different approach to performance tuning. Personally, I don't know anyone reputable who will put a truck on a dyne today. Good luck with your decision Gregg.

Stevens03 · October 2, 2014

I'm a big blackbear fan. He's done my 03, 07, and my 11. Highly recommend him if you can meet him in person.

Stex · October 2, 2014

Hello everyone,

I stopped by a well known performance shop Monday to set up a time to dyno the truck and have it tuned. They said they would only street tune it but couldn’t run it on the dyno unless I upgraded the driveshaft. This is the first I’ve heard of this. I’m wondering if they just had a bad experience.

I had over 742 hp and 1307 tq on my old dodge Cummins and never had an issue with the driveshaft after years of drag racing and sled pulling. I broke about everything else though.

Anyone else have any issues? 2014 6.2L 4x4 CC standard bed stock 20” with only upgraded CAI and exhaust.

Thanks,

Gregg

Please ask them and let us know.

2014 Sporty Shorty · October 4, 2014

Truck driveshafts aren't meant for the speeds you hit on a dyno. The 6l80 gives you a 1:1 in 4th, that's quite a bit of speed once you tap it out. I take it some of you have never seen a driveshaft let go on the dyno? Pretty scary stuff and it usually damages the dyno and the truck, or worse case, the poor bastard standing beside the dyno. All the tuning I've done has been on the street and the strip minus 2 times that was strapped down but I only ran in 3rd and I have 4.10s.

Crf450r420 · October 4, 2014

Dyno'd mine. Just used third and let the dyno calibrate to the gearing at 2000 rpm.

kstruckcountry · October 4, 2014

IMO a street tune is better than a dyno tune unless you're planning on drag racing the thing... I have heard a lot of people complain about the drivability aspect of dyno tunes. Versus a tune like BB that is done for both power and drivability.

Jon A · October 4, 2014

It's his dyno, if he doesn't want to risk it, that's his call. Just go somewhere else, dyno in 3rd gear and you'll be fine.

Personally, I don't know anyone reputable who will put a truck on a dyne today.

Actually I think the exact opposite is closer to reality--of the thousands of speed shops out there these days, a large portion of their business goes to trucks. They dyno them. I don't know of any speed shop other than PCMFL that has a blanket "no trucks" rule.

That said, I'm sure most use some judgement. Since most of the time they'll be the ones doing the tuning, they'll have control over whether the speed limiter will or won't be exceeded and by how far.

wilks3 · October 6, 2014

I wonder if the tube wall is thinner, to save weight, than it needs to be. Maybe causing the vibration in these trucks?

midwestdave33 · December 9, 2015

I wonder if the tube wall is thinner, to save weight, than it needs to be. Maybe causing the vibration in these trucks?

I'm wondering this too. I'm looking to upgrade mine. I have a violent loud metallic vibration/banging noise around 100mph. I'm scared to push it further ~ sounds like its coming apart. see my other thread