Max amount of power thru a bone stock L body trans?

[turbovanman²]

Driving my customers 86 GLHT again, TII conversion I did, 12 psi so far, no moly plate and its got a bit of noise, so how much abuse can we give it before kaboom?

Want to run it at the track, no slicks, just DOT's,

Stock TII setup, 2.5 inch exhaust, IC upgrade and a MP stage II computer.

[rosie]

Forza???

Both of mine let go, omniluvr's had 2 or 3 go. BUT, my second one lasted some serious mt. racing and 2 years with 190hp/200tq dyno'd at the wheels. 12psi 3" all the way

[rosie]

Forza???

Both of mine let go, omniluvr's had 2 or 3 go. BUT, my second one lasted some serious mt. racing and 2 years with 190hp/200tq dyno'd at the wheels. 12psi 3" all the way

[bakes]

it hard to say my a525 3.50 with a weld diff 2.5l turbo 14psi did 2 year ice racing and 2 years on the street with redline side steps and is still good to go .

[BadAssPerformance]

A525's issue is the case flexing due to the crappy diff and diff cover design. MP and LRE both made girdles for them to strengthen them.

[turbovanman²]

Hmm, I'll see if he want's to add one.

I guess no drag racing or higher boost until it gets one?

[black86glhs]

I wouldn't, unless he wants you to swap the trans with another one.

[ATaylorRacing]

I broke 11 5 speeds (even ones from turbo cars) in 100,000 miles in my high 15 second down to high 13 second CARB HO powered Horizon! The last one still broke with the stiffening girdle in place. I always broke the spyder gears. Then switched to an automatic that lasted 100,000 miles but always had to change fluid and filter and sticking solenoids every couple of months. The current automatic has over 73,000 miles on it and NEVER had a problem.....from day one it had a Cheetah FMVB AND Coan built a converter for it that had the bushinged part of the stator replaced with a large roller bearing. The tranny cover was removed and tranny inspected at 70,000 miles finding only peach fuzz on magnets compared to golf ball sized metal mounds and fluid looked new! I only launched it at 3000-3500 rpm when it was a stick.

[inplansight]

My old 86 GLH 2.2T2 18PSI lasted about six years drag and auto X. Only reason I went to the 568 was the low cost .

Paul B
IMO the 525 is a good trans if treated well

[OmniLuvr]

ive had some troubles from shifter forks, thinks its the 1/2, but its a very weak design, so if he is a hard shifter, those will break for sure, worse with worn shifter linkage, and this will cause the tranny to be in two gears at one time, locking the input and output together causing a kabooooom. with linkage problems ive also over shifted 5th gear, so the sincro doesnt stop once engaged, but slides over. this cause's shifter to be stuck in 5th, but syncros arent engaged so you have no forward motion, and you cant pull shifter out of 5th gear. also ive blown up spider gears, third gear on the output shaft from high rpm 2nd to 3rd clutch drop, and one tranny i broke the input shaft at the splines for the clutch.

but in the end, even if you shift sainly, traction is a 525's nightmare...

[OmniLuvr]

i should also add that i really didnt have major breakage problems til over 14 psi

[Vigo]

keeping in mind here that the torque a 2.2 puts out at a given boost level is WAAAY less than what a 2.5 will do.. its conceivable that saying you didnt have problems until 14 psi in the 2.2 is like saying you wouldnt have problems until 9 psi in a 2.5

Not that there's 2.5s involved here, just sounds like its not taking a whole lot of torque to break those things..

[1984rampage]

Dynoed 190 whp and 232 wtq and that was enough to destroy my 525

[OmniLuvr]

84rampage, what did you break?

[Ubmbass]

I really think it's all luck of the draw. I mean my friend's SC has several passes on his, full throttle shifting at 117 mph mid 12's and his is still going strong.

[rosie]

I really think it's all luck of the draw. I mean my friend's SC has several passes on his, full throttle shifting at 117 mph mid 12's and his is still going strong.

Till the syncro's wear out. If it's always been shifted nicely it'll definitely last longer than the 100-200k mile trans most of us get when we buy a used L body

[1984rampage]

I'm actually putting a Cliff R rebuilt 525 trans into my shelby charger.. We'll see how it holds up

[OmniLuvr]

ya, but i wanted to know what went out on ur trans?

[The Pope]

the case spreads past 200 W ft lbs, this makes them stick or miss 3rd. This I've done mostly with the GLHS's with more power and a stage 2, too much torque but rolling on the gas and no power shifting.

Dumping the clutch and power shifting causes the ring gear side bearing to give. They moved the bearing location on the 520/555/523/543/568 out to wards the wheel. The early trans has the bearing in past the ring so there is a ton of leverage on the ring gear spreading the ring and pinion apart. This deflection tilts the spider gears in the diff making them break.

A case girdle helps hold the diff in place so it doesn't deflect and nuke the spiders. The soft MP spiders take a lot more abuse as they bend some (softer race gears) instead of out right breaking. Lastly the chrome 3rd gear retainer will allow you to floor it in 3rd without spreading the case and nuking third.

Or throw it in the trash where it belongs and install a newer trans. Which is cheaper lol

[minigts]

I made 6 passes on slicks in one transmission, pushing 15psi and I ran my GLHS at 14psi at SDAC. Made 12 passes on street tires and no issues...yet. I'm sure it will break one day, but so far so good.