Replacement transmission is now fully installed, big thanks to
@OptimizePrime for having a LSD F35 that's in good shape available to sell quickly. Functionally the only difference is my final drive ratio is now 3.82 instead of 4.05. It previously had the counterweight on top of the transmission cut/ground off which I assume was to help clearance around the coolant hose and/or fuse box and electrical wiring.
This was the 1st time I've had my engine/transmission out of the goblin since it originally went in in 2019. I tried to see if I would be able to do it mostly in the frame but with the LSJ setup it looked like I had to pull it out to get the transmission to engine bolts all removed. Even if I could've gotten the transmission to engine bolt located near the starter out in the goblin, I think I still preferred to just have it on an engine hoist for the cleanup and installation.
I checked and reused my clutch (GMPP with upgraded throw-out bearing new to my goblin + a few thousand miles). I replaced the axle seals on the replacement F35 since I reused my LSJ axles so I could keep using my rear (cobalt front) wheel bearings. The axles may have the same diameter but I prefer a new seal if the installed axle changes, only reusing the seal when it's in good shape if it's the same axle being reinstalled. I did install the intermediate shaft that OptimizePrime included, I compared what I had and what he included and found that the bearings on my intermediate shaft were far more loose and noisy, especially when wet. Per ZZP info I used Redline MT-90 oil to fill the transmission. I used the shifter cable mount that was on the replacement transmission since I had one of the earliest design brackets that left the cables taking a sharp bend, the replacement bracket keeps the cables far straighter now (pictures below).
I also replaced my supercharger coupler and put in new oil. Might've been preventative only but occasionally I thought I heard the 'bag of rocks' sound from my supercharger at idle that went away with throttle which points to the coupler. It wasn't extremely loose but easy enough to do. Reassembled with GM adhesive and reinstalled on the intake of the engine.
When doing the timing chain work the other week I found the serpentine belt that I installed from ZZP last fall had 1 spot that had already broken 5 ribs to the mid point of the belt. Well, there were only a couple drives since then before the transmission broke and when I looked this time, all 6 ribs were broke. New belt is installed, still from ZZP since their belts are such a good price compared to local for me.
Bleeding the clutch unfortunately went just like it did in 2019... I know how the clutch elbow/throw-out bearing/connections work but just didn't seat the seal on the top end of the clutch pipe all the way down. Everything clipped together but as you might expect when I started working on bleeding it I was merely dripping brake fluid down the clutch pipe into the bellhousing. I'd estimate I lost ~1/8 cup fluid there which is almost done dripping out after 3 drives. I did spray some brake cleaner into the bell housing as well to wash an fluid off the clutch and pressure place and leave it just at the bottom of the bell housing. I didn't feel like pulling the engine back out to clean that area since I know it's dripping out and will finish sometime in the next few drives. I hadn't yet installed the subframe at this point, nor the fuse block, just to keep it easy to reach the clutch bleeder valve.
After fixing the seal at the top of the clutch pipe and pushing it far enough down I then reassembled the clutch system and worked on bleeding it. Initially I tried it solo per the GM instructions with a vacuum bleeder on the reservoir but I went back to essentially the method Lonny described a few years ago and is how I bleed my clutch originally with 1 difference: bleed the main line like it's a brake caliper (1 person pump the pedal multiple times, hold the pedal down, 1 person open the bleeder, close the bleeder, release the pedal) and then bleed the throw out bearing (pump the pedal multiple times, hold the pedal down, open the bleeder, release the pedal, close the bleeder). The difference I do is that I don't just drain to a cup, I hook up my vacuum bleeder to the transmission bleeder and keep vacuum on it. It took some time but I eventually was getting pure smooth brake fluid with both types of bleeding. I did need to add a zip tie around the drain hose at the bleeder to keep it from just pulling air into the hose that wasn't actually in the fluid. No fluid drop in the reservoir after a few drives and the amount of dripping from the transmission to engine surface is nearly none now.
Refilled the intercooler coolant and ran the intercooler pump a few times till the level no longer dropped, that's an easy system to finish. I then refilled the engine coolant through the passenger side block connection, first topping off what's in the engine and then pouring it down the coolant tube that runs to the radiator. Reconnected the coolant hose to the engine and finished filling up the reservoir. I haven't needed to add any coolant since then, I think I got the system filled with essentially no air bubbles this way.
Newer style shifter bracket, unless OptimizePrime welded the adjustment himself:
For reference, this is how far the driver side axle installed into the transmission, based on he previous dirt lines from my old transmission, this seems to be all the driver side does. The cup can play a small amount in and out (maybe 1-2 mm) but the exposed bright shaft portion at the seal is only ~1/8".
I added some anti-seize in the splines for the passenger axle to the intermediate shaft (actually also on the splines to the wheel bearings too). The passenger side axle easily slipped/clipped into it's fully seated spot:
I currently have a 4.05 LSD F35 transmission with a failed 2nd gear synchro sitting in my garage, I need to figure out what's happening next to that. I also have a pair of LNF axles in good condition and 1 intermediate shaft that is ok but might need a new bearing before too many miles if it's installed again.
Glad to hear your cruise is back working again.
