LB7: Tcase 261-263 breakage

Muff

Muff

Just Learning
Oct 7, 2013
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Butler, Pa
Guys running the 261-263 tcase in drag racing applications what kind of breakage are you experiencing, and at what power levels do these seem to become troublesome? Im trying to figure out what tcase to couple with the 4l80e ill be running. The gentleman i'm sourcing parts from is a old time GM guru to say the least and is strongly against me running the 263 thats currently in my truck. He is more old school gas though, let me know what you guys think.
 
thunder550

thunder550

Active member
Apr 2, 2013
1,176
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Phoenix, AZ
I have never heard of someone breaking a 261 or 263 (or any of the late GM transfer cases, for that matter) with too much power. Every failure I've seen is from a lack of maintenance or lack of fluid from pump rub. The 261/263 are some of the strongest transfer cases out there. What is your guy recommending that he thinks is better?

Does the 261/263 work with the 80E? I know the bolt patterns are the same but the input gears would have to be different, I think the output shaft of the 80E is smaller than the Allison. If I had an 80E I'd be tempted to try the 149 AWD t-case and see if it would hold up, but that's for me in a lighter weight more DD application rather than racing.
 
PureHybrid

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,517
501
113
Central OH
Some of these old guys have serious hard-ons for heavy useless technology. I was talking to an older gent at work about doing a 4wd swap on mine, he said to run a divorce case np205 :roflmao:
 
TheBac

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,677
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Mid Michigan
In the 7 years Ive been here, I cannot say I have ever heard of anyone wrecking their Tcase racing or pulling.

Transmissions - yes. Engines - yes. Front/rear diffs - yes. But no Tcases.
 
CarolinaHD

CarolinaHD

Member
Feb 8, 2011
969
6
18
NC
Something let go in my case that allowed the main shaft to move significantly and wreck my case. Cracked both sides of the case and had to get a reman. I think it was more of a fluke than anything. My case always had fluid in it and the pump rub plate since 60k miles.

And to add to what Tom said, the truck was only run down the 1/8 strip 10 times and rarley did I use 4x4. The one time I actually needed it is when it broke and left me stranded 3 hours from home.
 
Muff

Muff

Just Learning
Oct 7, 2013
1,063
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Butler, Pa
thunder550 said:
I have never heard of someone breaking a 261 or 263 (or any of the late GM transfer cases, for that matter) with too much power. Every failure I've seen is from a lack of maintenance or lack of fluid from pump rub. The 261/263 are some of the strongest transfer cases out there. What is your guy recommending that he thinks is better?

He wants to run a ford np205 because it has the driver side drop. I really don't think that's necessary as the 263 seems to be stout. I know caleb was busting them sled pulling but that's a different story.

Does the 261/263 work with the 80E? I know the bolt patterns are the same but the input gears would have to be different, I think the output shaft of the 80E is smaller than the Allison. If I had an 80E I'd be tempted to try the 149 AWD t-case and see if it would hold up, but that's for me in a lighter weight more DD application rather than racing.
Click to expand...

Ya I'm going to have to change something to make the 80 mate with the 263, but that shouldn't be to hard.

PureHybrid said:
Some of these old guys have serious hard-ons for heavy useless technology. I was talking to an older gent at work about doing a 4wd swap on mine, he said to run a divorce case np205 :roflmao:
Click to expand...

Exactly!
 
zf>allison

zf>allison

you never had your car.
Apr 30, 2013
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elsberry mo
I say that because it's what I was told. It would act like it popped in neutral. Never ground to anything happend right after I bought it
 
Noreaster

Noreaster

Active member
Jun 13, 2007
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Cape Cod,MA
TheBac said:
In the 7 years Ive been here, I cannot say I have ever heard of anyone wrecking their Tcase racing or pulling.

Transmissions - yes. Engines - yes. Front/rear diffs - yes. But no Tcases.
Click to expand...
you must have not been paying attention, mostly pullers but a couple of drag racers I can think of
 
ikeG

ikeG

Oughta Know Better
Apr 19, 2011
2,472
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Western PA
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Numerous cases fail in 2.6 class every year. Insane power + extreme traction + strengthening every other drivline part = tcase letting go. Twisted main shafts, collapsed sprockets, chains breaking and going through the side, etc etc. Probably will never see it fail consistently in any other application though.
 
meshanic

meshanic

All In Trucks
Dec 9, 2010
436
0
16
West Texas
Don't pullers usually run in 4 low? I've seen guys destroy a planetary using them to tow heavy loads in the fields but only in low range. 4 hi seems to hold up to all kinds of abuse. I know the guys from atp just run a pump upgrade on a stock t-case for all the racing they do.
 
Muff

Muff

Just Learning
Oct 7, 2013
1,063
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36
Butler, Pa
meshanic said:
Don't pullers usually run in 4 low? I've seen guys destroy a planetary using them to tow heavy loads in the fields but only in low range. 4 hi seems to hold up to all kinds of abuse. I know the guys from atp just run a pump upgrade on a stock t-case for all the racing they do.
Click to expand...

Anymore info on the pump upgrade
 
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