2003 Pro-charged Marauder 4R70W transmission rebuild

[88grandmarq]

Marauder owner from Miami contacted me about rebuilding the transmission in his Marauder. He had his local repair shop remove the transmission from the car and shipped the transmission to me.
Transmission arrived in a few days and I wasted no time getting it apart . The residual fluid was dark red. The filter had separated from the grommet and the filter was laying in the bottom of the pan. The Forward clutch piston seal was cut and the forward frictions were burned and worn to the metal, the clutch pack had gotten so hot the top clutch plate was warped/wavy. The sun gear and planetary gear bushings were scored from debris and in turn, scored the direct drum snout. The OD band was burned and the extension housing bushing was worn. The transmission had previously been built and I found the front pump was not seated and very close to coming unseated.
The transmission was completely rebuilt. I replaced the direct drum, planetary gear and sun gear. Because this was a supercharged engine, making an estimated 550 HP, I did my usual improvements during the rebuild; lubrication improvement, 300m intermediate shaft, updated one way mechanical diode with spiral locking ring and updated OD band. The valve body was also rebuilt with Tuff plate and Sonnax valves were installed. Jmod was performed for firm shifts. After the rebuild is completed, I install a test plate and used low pressure compressed air to test all the clutches for proper operation and this one was working correctly.
The transmission was strapped to a pallet and shipped back to Miami and the local repair shop installed the transmission.
The vehicle owner contacted me saying the transmission was shifting erratically, would not shift into 3rd gear and the speedometer was going wacky. The OD light started flashing and code p0720 was stored. The repair shop replace the OSS and the same symptoms and code happened. with the car being out of state it was impossible for me to diagnose over the phone/internet and it had to be tuned for the supercharger anyway, so the vehicle owner towed the car to Mo's speed shop in Dallas Ga. I took time off my day job and spent a half day at Mo's speed shop looking the car over and making sure there was no transmission problem. I was able to test drive the car and confirm the symptoms and stored code, but could not find the problem. Jeff at Mo's speed shop agreed it was something electrical and he would have to dig into it and find what happened. Turns out the replacement, aftermarket OSS the repair shop in Miami installed was faulty. the sensor was replaced and I am told the transmission is performing shifting and performing correctly now. The car will get an injector and fuel pump driver upgrade in the next week and go on the chassis dyno to get professional tuned.

[Catfish]

It's obvious from reading your post you're very knowledgeable about our transmissions. If I ever have any issues with mine I'll be contacting you.

[8UWITH6]

Transmissions suck. Glad you know what you are doing on them. LOL. My Buick had to be redone twice because of a small piece of metal stuck in a fluid port/check valve in the case.

I also managed to tear the 2-3 piston seal in my blue car shortly after performing a J-mod. It would shift to 3rd under moderate throttle but not shift out of 2nd under light throttle. Dropped the valve body replaced the piston bolted it back together and its been fine for 10k miles.

[cer0413]

Transmissions suck. Glad you know what you are doing on them. LOL. My Buick had to be redone twice because of a small piece of metal stuck in a fluid port/check valve in the case.

I also managed to tear the 2-3 piston seal in my blue car shortly after performing a J-mod. It would shift to 3rd under moderate throttle but not shift out of 2nd under light throttle. Dropped the valve body replaced the piston bolted it back together and its been fine for 10k miles.

Will be in touch

[88grandmarq]

I also managed to tear the 2-3 piston seal in my blue car shortly after performing a J-mod. It would shift to 3rd under moderate throttle but not shift out of 2nd under light throttle. Dropped the valve body replaced the piston bolted it back together and its been fine for 10k miles.

I remember you posting about that. that was an odd issue, but I have seen it happen before when people remove the 2-3 accumulator spring during the J-mod.

removing the spring causes the 2-3 accumulator piston to wedge in the bore in extreme cases, causing the damage you experienced.

[88grandmarq]

btw... Forgot to mention;

installed a U-haul trans pan with drain plug
installed a auxiliary trans cooler
filled with Amsoil fully synthetic fluid

[babbage]

Nice job/write up!

[8UWITH6]

I remember you posting about that. that was an odd issue, but I have seen it happen before when people remove the 2-3 accumulator spring during the J-mod.

removing the spring causes the 2-3 accumulator piston to wedge in the bore in extreme cases, causing the damage you experienced.

Yep. If something odd can happen, it happens to me.

[Cobra432000]

Thanks for taking the time and detailed work to get me to rolling 88grandmarq. I've had the car 6 months and been nothing but problem after problem. But guys please know that 88grandmarq is someone you can send your car to and not worry if it's getting done right. 88grandmarq fully informed me on every detail that he would perform, just as he just did here to you guys. He then kept me in the loop throughout the whole build process. After receiving my transmission back from 88grandmarq, reinstalling, and having further issues due to a faulty sensor. 88grandmarq went back and forward with me throughout his work days to figure this problem out. Finally after getting no where, I towed my car 12 hours to Mo's Speed shop (where Mo's Speed Shop is just as anal about keeping me informed with every little detail about my car). 88grandmarq came and verified that is wasn't mechanical, trans is now fixed and waiting to hit the strip after further repairs from Mo's. Through my experience this guy knew exactly what was wrong and fixed the problem. Give'em a call, you won't be disappointed!

[martyo]

Eric (88grandmarq) is like some sort of mad scientist when it comes to these transmissions!

HUGE PROPS!!

[hotford]

Talk about customer service.............PROPS to you!!!!!

[88grandmarq]

Thanks for taking the time and detailed work to get me to rolling 88grandmarq. I've had the car 6 months and been nothing but problem after problem. But guys please know that 88grandmarq is someone you can send your car to and not worry if it's getting done right. 88grandmarq fully informed me on every detail that he would perform, just as he just did here to you guys. He then kept me in the loop throughout the whole build process. After receiving my transmission back from 88grandmarq, reinstalling, and having further issues due to a faulty sensor. 88grandmarq went back and forward with me throughout his work days to figure this problem out. Finally after getting no where, I towed my car 12 hours to Mo's Speed shop (where Mo's Speed Shop is just as anal about keeping me informed with every little detail about my car). 88grandmarq came and verified that is wasn't mechanical, trans is now fixed and waiting to hit the strip after further repairs from Mo's. Through my experience this guy knew exactly what was wrong and fixed the problem. Give'em a call, you won't be disappointed!

when do we get burn out videos?

[88grandmarq]

Marty from Mo's performance tells me the car dyno'd at 493 in 90 degree heat.

[Cobra432000]

Burn out as soon as she's back in my arms!!! Mo's Speed Shop is massaging her up right now.

[88grandmarq]

Marty from Mo's performance tells me the car dyno'd at 493 in 90 degree heat.

BTW... this number was achieved on the stock exhaust. Headers and better exhaust currently being installed.