Ohiocruiser

I actually am surprised to hear all those examples. Always was under impression that auto transmission was one of the strongest part on hhr.

RJ_RS_SS_350

I think that's what's referred to as anecdotal evidence.

dougcjohn

So question still hanging:
If not swapping to 5sp, remaining with an Auto Tran, and stating the 4T45E isn't idea.
What is suggested or is there a "bullet proof" build kit to overall the 4T45E.
Along with Trany, is there a specific Torque Converter that should be considered too?

I'd think with the popularity and quantity of the 4T45E, there would be kits to strengthen.

OshawaHHRss

I have part numbers and stuff for a transmission build but the weak link is the clutch packs. All the upgraded raybestos clutchpacks are discontinued and on worldwide backorder and have been for over 5 years. The gm racing 45e stuff is super rare and costs a fortune. You could put a small diameter high stall converter on it, and I could dig up the part numbers for the 7/8 drive and driven gears for 3.91fdr. You could use a team green lsd insert too. Just sort of pointless, if you know you’ll melt those stock clutch packs. They can’t handle being launched with any boost either. If you did everything you could to it and had a solid trans tune it might last for a long time if you keep on top of fluid changes. I used to do mine every 10k miles. But if you make anything more than bolt ons power it’s a ticking time bomb

OshawaHHRss

If you were dead set on racing and keeping it auto, you could make a 4t80 work

PulpFriction

I’m unlikely to ever race the car (at least I haven’t caught the bug. Yet.) but this forum has convinced me the factory “stage 1” tune is a no-brainer, and the local Chevy dealer is willing to do it. Sounds like in this case sticking with 4T45E would be acceptable and better stuff will cost more. Will definitely check out the solenoid b4 shopping transmissions. What if I said the only problem is no reverse?

My perspective, I’m not a professional mechanic but have busted my knuckles from time to time. I had a career in engineering, designed a few industrial gears and even did a tiny bit of automotive design but know next to nothing about automotive transmissions.

I’m a sponge for this stuff though and am blown away by the breadth and depth of knowledge here and what I’m learning.

Now I have questions about my SS 5-sp, for which I should probably start another thread but I want to quote some comments here. Lemme think about that.

RJ_RS_SS_350

Here's something interesting, you may have already seen it. ZZP has a kit to transform your 5-speed into a 6-speed.

PulpFriction

uh YEAH, because the first time I drove the thing I loved it but though, “this car could use one more gear,” and by all accounts many agree. Gotta be trade-offs?

OshawaHHRss

instead of going with gms1, buy two 3bar map sensors off rock auto and get a tune. The gms1 tune doesn’t do much for the tranny. Way cheaper to do it that way. If you’re looking at upgrading your F35, ottp makes a nice short throw shifter and 4H tech makes a really nice short shifter arm. Gmpp clutch is the best for the money unless you can find a new in box one that’s better. I swapped my stock 4.05lsd F35 out for a 3.82lsd F35. The longer gears are nice on the daily

also, the 6 speed F35’s are sold through jason perotto at B3. Zzp sells an F40 swap but you could piece it together cheaper