Frame distorsion.

ecc_33

Junior Member
Aug 10, 2006
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Amanda, Ohio
My dad also has the same lift and his half shaft flange is the same distance from that a-arm bolt as mine is. The damn bolt cant be 1/4-1/2 inch away from the diff/shaft flange.
 

ecc_33

Junior Member
Aug 10, 2006
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Amanda, Ohio
Correction, Its not the bottom rear a-arm bolt thats hitting the half shaft flange. Its the sub frame bolt that holds the subframe to the frame. I have taken my t-bars bolts out and trying to work on a fix for this still. I will see what happens the next pull:eek:
 

Jared Duramax

<---- $$$ Whore!!
Feb 13, 2008
1,052
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Matthews NC
i am stock height and i havent seen any movement in that shaft. i check that after every pull and everything is looking good. Do you think it has anything to do with hanging lots of weight and offsetting it on the front?
 

hogdoghd

Adrenalin Junkie
Jun 24, 2008
91
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Oxford, Ohio
I have quite a few hooks on mine and have seen no problems. I hang 700lbs + my 300lb arb bumper = 1000 lbs on the front. I dont think that its the weights, I am keeping a close eye on this though! I was running green keys at the beginning of the season and had a bad toe in problem so I went back to stock keys and a straight center link and now I am good to go:D
 

hogdoghd

Adrenalin Junkie
Jun 24, 2008
91
0
0
Oxford, Ohio
Ok I spoke to soon I was under hogdog yesterday changing the oil and HOLY SH*T the front drive shaft has rubbed on the tranny bellhousing:eek: The u-joint cradle on the front, front driveshaft has wore about a 1/4 inch off of the aluminum.:mad: I guess its no big deal but dam, I cant believe it, as good as I treat my truck and as much as I baby it.:rofl::angel: I'll post pics later.
 

bullfrogjohnson

Big Girl!
Nov 20, 2006
4,167
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Locust, NC
Yea it happened again last night. I think im going to take the pan hard bar completely out and see what happens. All mounts on the lift and diff are good. The a-arm bolts are installed correctly and are good. Since I have been running 35's on 16x10 rims I do have the torsion bars cranked in about 4 turns or so. But nothing major with absolutely zero tow in or funky front end dancing. I do also hang 1000 pounds offset to the drivers side alittle

I am running the exact same setup but with 33's
 

sweetdiesel

That's better
Aug 6, 2006
10,390
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Thailand
Everyone that has had this problem that is lifted has it with either the green keys and/or a 4" lift. Like Todd said, are the stock height guys or the 6" lift guys having this issue as well?

Geuss im not a puller ,but do pull heavy trailers and have had some high HP tunes in my truck a couple times:baby:

7" lift and no issues with the front shaft.....untill I say that :eek:
 

Jared Duramax

<---- $$$ Whore!!
Feb 13, 2008
1,052
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Matthews NC
i think this is the problem
stock height - shaft above the bolt no rub
4in - shaft at the bolt lots of rub
6in - little below the bolt
7in - way past the bolt
 

knagel

weakest link finder
Jun 4, 2007
221
1
18
Central, Iowa
Sorry I haven't read the whole thread but I had the same problem earlier in the season and it ended up being the left motor mount was ripped. Looked fine until you pryed on it or put it under load and it allowed everything to pull up and to the left allowing the front shaft to rub the tranny. If this sounds like what you have going on PM me and I will walk ya through the fix.
 

ecc_33

Junior Member
Aug 10, 2006
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Amanda, Ohio
Last night was the first night with the 35's and T-bar bolts completely out. Well I still havent found the problem with the front diff cause i was building boost coming off the line and POW the passenger side half shaft gernaded at the diff. Came back and possibly took out the lower part of the shock. More details to come. Im going to go rip it apart now:mad: A nice dana 60 is sounding better each pull :( Problem is i still really dont know what to do to fix whatever issue im having. Never heard of a 2.5 turbo truck breaking half shafts:confused: Question is which half shaft do you buy to replace it with? Advanced or Napa? Dont want to buy some rebuilt piece of shit one
 

durallymax

New member
Apr 26, 2008
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Under The Hood
I have grenaded two passenger side CVs this year. One was a 20psi boosted 4x4 launch woth the front end in the air. How I boosted to 20psi I dont know. Ridiculous tune I guess.

Why was I doing it?? Somehow I got the rep of the fastest truck in the area (doubt it) so 5 kids piled in and wanted a boosted lauch. Went about 20' and snap. Thought it was a tie rod but ended up being the shaft.

At the time I didnt know what I was doing and just wanted it fixed so I had the stealer replace it. I have a good dealer and they said you can pay $900 for a GM shaft to be put in or $330 for a shaft from weaver auto parts. Obviously I chose the cheap route. They had never seen a broken CV like that In all their years. I didnt know whether to feel special or like an idiot.

Then A few weeks later at a pull I still had about 4 turns in my t bars and was runing caltracs and 9" blocks which block the frame solid about an inch over stock. The truck bounched a little then snap. The whole crown went oooooo, they thought I was done then I pinned it. Still ended up 6th and going 236' in 2wd. Sad thing was that it was my best pull of the year at that time.

I had a pull the next night and weaver was the only place open on sunday so I got a New shaft from them, not a reman. I also found out that it was fre as the shaft the stealer put in was from the same compay and still had a warrenty.

I had no idea what I was doing but in less thn an hour I had the new shaft in.

Then got a$$ packed by the sled. Needless to say the caltracs were removed and never put on again.

Heres a vid.

http://www.youtube.com/watch?v=7EX6OnXafng

Now I know cognito as beefed up shaft but its not the shafts or joints that fail from what Ive seen. Its where it bolts to the front diff tube. Are cognitos shafts beefed up there?? Dont wana waste all that money on nothing.

The passenger side shaft will always break first and if you dont have a locker you shouldnt break the driver side shaft.

Now my questions.

My truck will be sitting in pieces all winter in our shop on the lift. Im doing a number of things to it, and frame/suspension setup is one thing Im really focusing on. I really want to get the power to the ground and still be reliable. I learned a lot about what works and what doesnt this year as you can see by my video on here.

I dont want to thread jak so ill only ask what I need to do to prevent frame distortion. If all goes as planned Ill be running an A5K and duel fuelers as well as rods so I dont put a window in the block.

I dont like lifts so my truck is stock height. I take the Tbar bolts out and hang between 900 and 1200lbs out front.

My new blocks will be designed so that the truck sits level when pulling. I think I blocked too high this year and lot a few feet because of it.

Ill also be running STSs so the truck will really be hooking up.

I havent noticed any distortion but also havent payd attention either.

Any ideas for what I should do to prevent this for nxt year?? Is this B&B bar working?? Do I need solid motor mounts??

Ive got plenty of time and sponsors money to spend so all Ideas are welcome.

Thanks guys.
 

ecc_33

Junior Member
Aug 10, 2006
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Amanda, Ohio
IMHO dont waste the time on the pan hard bar....I would definatly bolt the driver side motor mount together,.....Well just got done tearing the truck apart and ended up getting an advanced half shaft that is lifetime warrantied:rofl: It looks different then the original so well see how it holds up....I think i found a lot of the problem with the diff hitting the sub frame bolt. The two ears that bolt to the front of the diff mount were bent severly towards the drivers side. So i loosened all the diff mount bolts, straightened the tabs, took a come along and ratcheted :eek: the diff back towards the passenger side then tightened everything back up....Looks way better now and lots more room. Also i noticed that the side of the diff was contacting the subframe alittle bit. Now it looks the same as dads underneath if not better so I will see how it holds up. One question I know on the rear diff the pinion wants to rotate upwards under power, So does the front follow the same concept or does it rotate down? sorry for the dumb question. Good thing I had the E-locker last night or I would have never got it back onto the trailer
 
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JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
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Texas!!!
One question I know on the rear diff the pinion wants to rotate upwards under power, So does the front follow the same concept or does it rotate down?
It wants to go down. Either housing will want to rotate the opposite direction of the tires.
 

juddski88

Freedom Diesel
Jul 1, 2008
4,655
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63
Chesterfield, Mass.
IMHO dont waste the time on the pan hard bar....I would definatly bolt the driver side motor mount together,.....Well just got done tearing the truck apart and ended up getting an advanced half shaft that is lifetime warrantied:rofl: It looks different then the original so well see how it holds up....I think i found a lot of the problem with the diff hitting the sub frame bolt. The two ears that bolt to the front of the diff mount were bent severly towards the drivers side. So i loosened all the diff mount bolts, straightened the tabs, took a come along and ratcheted :eek: the diff back towards the passenger side then tightened everything back up....Looks way better now and lots more room. Also i noticed that the side of the diff was contacting the subframe alittle bit. Now it looks the same as dads underneath if not better so I will see how it holds up. One question I know on the rear diff the pinion wants to rotate upwards under power, So does the front follow the same concept or does it rotate down? sorry for the dumb question. Good thing I had the E-locker last night or I would have never got it back onto the trailer

Why wouldn't you waste your time on it? it has helped other trucks. IMHO i think for a street-driven truck, solid or semi-solid motor mounts would be pretty uncomfortable. but then again, i have never driven a dmax with altered mounts before.
 

JOHNBOY

< Rocking the Big Single!
Aug 30, 2006
2,159
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Saegertown, Pa
If you bolt the motor mounts like I did in my DIY thread you will have no added discomfort. The only thing different is that you would have that awful clunking noise when the stock mounts break.;)