chrisc543

Hello,

I have sheared my final drive on my gsr swap with a b16 trans that has a 4.4 final drive. From what I am reading this shouldn't happen until over 300whp and the guy I bought the swap from said it only had 205whp. Not sure why it stripped out so badly. It is completely sheared. I will try and get pictures up later tonight of the wreckage.

My question is if anyone has replaced the final drive from 4.4 to 4.266. I cannot find an Mfactory unit that is 4.4 and want to put a heat treated vs OEM back into it. If anyone that is NA has used 4.266 final drive will I notice a huge acceleration difference? I haven't had car to track I just finished the swap and 600 miles later blew the transmission. Also any tips on why it blew? I have a 8 puck (maybe 6 don't remember) stage 2 sprung clutch and stock wheels and tires. I wasn't even beating on it when it broke. I did have one time where wheel hop was pretty bad but always got out of it right away. I just don't want to keep taking trans out as I hear other people do when making way higher HP. I'm using steel mounts not sure if changing to innovative would make a huge difference. Also on a pretty tight budget.

Also this is supposed to be my DD so much for that after a GSR swap.

Thanks in advance.

Aquafina

iTrader: (3)

Wheel hop, fluid, power, traction, and many others are reasons why it could have broken.

MFactory has a 4.266 and 4.533 FD (among many others). Those are the closest you will get to the OEM 4.40 from MFactory.

doTERRA

From what I've read, the B16 has a weaker final drive gear and it was beefed up in the B18+'s. Totally sucks that yours broke, though.

0parts@synchrotech

Not exactly true. They both share the same exact countershaft. The outer teeth on the ring gear are the same. The only difference is the inner diameter is larger on the B18C models vs. the B16 where it mounts to the differential. So they are not beefed up in any way on the B18C models

chrisc543

Wow thanks for the great write up of detail. I needed that I am going to be trying to rebuild myself.

Anyways I still haven't had time for pictures or counting of teeth to see what mine is currently at.

I am scared to go to a shorter final drive it already was sitting at almost 4k on freeway. If I go taller will acceleration drastically be different from 4.4 to 4.26 that seems so minimal so not sure what the impact would be. Also I was thinking if I do the 4.5 FD then I could do the LS 5th gear to get back to around 4k on freeway.

I just don't want to have to keep taking apart. Want to drive for more than 600 miles. now I will probably baby it so doesn't matter what the FD is LOL.

Aquafina

iTrader: (3)

You will notice a small difference dropping down to the 4.266.

Don't worry about cruising RPM. Keep your foot out of it and gas mileage should increase. Unless you plan on putting 200k on it, then longevity won't be an issue.

I cruise at 4,950 RPM in 5th at 80mph with my D16 with no issues.

chrisc543

Well like I said in my first post it is supposed to be my daily driver. I drive a lot so not sure what to do. 35k a year. I think going to the 4.266 final might be my better option.

Do these use the same shim as stock? Also any write ups on how to test run off?

I've never rebuilt a transmission but from the looks of the b16 doesn't seem overly difficult. Plus the great write up on here for doing it. Minus its on the main shaft instead of counter. My other question was on the countershaft nut at top it was an open bearing is that correct. Wondering why that wouldn't be a ball bearing like the rest.

Thanks for feedback appreciate it.

Aquafina

iTrader: (3)

The final drive doesn't use a shim. The FD is comprised of a ring gear mounted on the differential and the countershaft.

The 2nd to top bearing is a roller bearing, the top is a ball bearing with circlip groove.

chrisc543

Well here are some pictures of the wreckage.

Teeth completely shredded.





This is the bearing I was trying to describe.


So I think I am going to try and get the final drive. I just got a service manual. Hopefully will be back on road soon.

Any tips to not shred the new one. I didn't drive super hard but it did spin tires going into second and third sometimes when really in it.

doTERRA

Sorry about my comment being wrong.. It's actually the differential that's stronger, not the final drive.

I know ATS advertises their final drive gears as being stronger than factory. I have an extra of their 4.928 drives with an LSD and it is holding up nicely.

The ultra short 1st gear is great for city driving, my near 1000 rpm crawling speed is the same as many automatics creeping speed so it's unbelievably easier to stay in line. Some online call 1st useless, but my stock GSR engine can't even spin the tires from a stop (except when it's wet) even with light 14" wheels with all seasons so traction hasn't changed for me. All it needs is a longer than GSR 5th, IMO, as I'm averaging a hair above 33 mpg instead of 37-38. Coming from the stock GSR 4.4 it makes the car feel a significant amount faster.

Not sure what you'd lose going from a 4.4 to a 4.266 though it is only a little bit over a 3% torque multiplication loss. The 4.928 FD is 12% higher than 4.4. IMO if all these torque changes were 4x smaller than what I felt from 4.4 to 4.928 I don't think I'd be able to feel it.