I went a to a few trans shops today. My transmission has this horrible shudder off the line and it feels like its jumping as opposed to a nice burnout. However its random and happens about 1 out of 10 launches

I took it to aamco first, the guys were morons, they were not interested in a test drive kept reassuring me that they would replace "everything" but the guy was not sure what that refered to when I asked him...second I took it to another shop, the guy was not interested in selling the product, he wanted to take a test drive. the guy test drove it and said the reason the transmission was "jumping" off the line was because of the summer tires I had on the car. I left. The third shop addressed me the same way, did not try to sell me on a rebuild but wanted to test drive as well. They said it was the torque converter slipping against the flexplate causing it to slip. the 4th shop would not do a test drive until wednesday. 5th shop. The winner.

First thing I see up front is a 97-99ish GTP up on one of the 5 lifts or so. The service manager/owner Jason is at the front desk. Before I even said anything, Jason asks me what size sc pulley I have on the car and if I'm modded . I was like, holy **** this guy knows something about 3800'* lol. Apparently he owned a 93 SSEi for 3 years that he rebuilt the motor from the crank up with a cam and DIY ported heads So I'm thinking cool, a trans shop that is cool with me modding the car...thats alright. One of the only nascar tracks in the northwest is located in Twin Falls, and apparently this shop builds most of the trans'* for them. the head builder dude Tony and I took a test drive, He abused the trans in everyway possible to try to isolate a diff or planatary gearset problem...flooring it on a turn, launching at 3000RPM in Drive and Reverse...etc....He drove the car harder than I've ever seen someone drive a bonneville lol. Well maybe with the exception of Todd and the dumpster incident. Anyway tony'* bet is on a couple missing sprockets or whatever they are called on the gearset, not a diff problem. The crap tires are going on this car soon since I know they are going to "test" the trans quite a bit. we probably lost a good 3/32 of tread in about 10 minutes today lol.


So it looks like its going to get rebuilt next week. Tony pointed out that the 4t65'* and several other gm fwd trans have the problem with the 4th gear hub/shaft assembly. Thats a given, so is the planetary gearset.

Here is the tenative list:
Torque Converter - probably stock
Master Rebuild Kit - not sure of brand
Shift Kit - Not sure of brand
4th gear hub/shaft - he mentioned "hardened", not sure of brand
"Hardened drum assembly" - not sure what this is
Engine Mainseal/crank seal gasket
trans mounts, replace 3 of them regardless of condition, they have 180K on them.

that is the current list, perhaps others who have had their trans built recently would have some advice on what to replace while they are inside, anything that could fail or that should be beefed up to prevent the trans from puking. LSD is out, gear change is out, I'm open to all other suggestions

Meanwhile the manager/owner expressed interest in my 93 SSEi after the trans is built, I may just trade the car on a trans rebuild for the 98, we'll see.

So what other goodies should I put in there?

This looks like a standard rebuild. Nearly any rebuilder out there replaces the worn/wearable parts and installs a basic shift kit.

I'll move this to the proper section for you.

Generally, the "Hop" you are speaking of is generated from your Input Sprag Roller clutch, it turns one way when you release the gas peadle, when you re apply it locks back into place to apply power to the mainshaft/chain/output shaft, when it jumps a few times you get hop, it can only get worse. Trust me, after 5000 kms, mine is DEAD in my car, its going in this week for warranty work and a stronger clutch, plus a few more PCM mods.

I'll bet you cash thats the problem starter right there, that hop is bad for everything else though too, especially your differential

Wow I would be pissed if I took my car into a trans shop and let someone test drive it and they beat it like that.

My car just did this "hop" too the other day, I’ve only felt it a few times. But @ almost 170k it’* rebuild time for sure. I found your response rather informative Matt as I know very little about transmissions myself.

Ed

If that clutch spins around compleatly, it will likely take other components with it. Think of it as your socket wrench, locks one way, free wheels the other, when that lock gives out when youre touqing on something, what happens to your hand as it nailes an exhaust clamp at Mach 2? ow.

In talking to the guys at Intense while there for the trans build....I learned and forgot more than I wish to mention.

3rd gear sprag can be replaced with a ratcheting sprag, clutches can be upgraded, it'* a good idea to replace the wiring and all the soleniods. Hardened input and output shafts are a wise choice.

If I stand on the pedal from a dead stop, sometimes, my bonnie shutters, shakes wheel hops until i let off. Sooo.. I don't stand on it. Is this the kind of symptom you are getting?


Thought the front brakes where not releasing so i was going to change the flex brake hoses.

This just happened to me this morning. A week ago before that. Seems like something is F'ed up somewhere in the drivetrain or the suspension. Im going to need a winning lottery ticket to repair this thing.......... eventually.

http://www.intense-racing.com/Mercha...ategory_Code=T

so will that kit fix my jump issue if that is indeed the problem?

I'm about to hit the order button and go down to the trans shop to talk about retrofiting to the pawl style design.