Thread: #137B 2A FC rebuild

Conundrums...
I set up the engine and drivetrain so I could run a std 88/109" front drive shaft in the rear. This positioned the engine abt 200mm back from where it would normally be, just behind the seat box. This has advantages in terms of noise, seat height mounting options and moving weight rearwards. My issue is that the rear driveshaft has about 10 degrees of deflection through it. A bit high but I don't know if TOO high?? If I move the engine forward it only reduces to 8 degrees and I need custom driveshafts made.

At the front I've had to have a custom mid-mount bearing shaft made to clear the bellhousing. Moving the engine forward doesn't avoid this conflict.

How much is too much deflection angle in the rear driveshaft???

Another option would be to rotate the rear axle up so that the pinions were not parallel but equal angle in the opposite direction?? Obviously as soon as the spring height changed with loading, the angles would go out of whack...

Looks much the same as a 101 rear drive shaft - they are very steep but work OK. Remember the 101 is mid engined with the shorter 101 wheelbase.

Agree - the 101 is very similar if not worse than that. The front of the 101 is much worse.

Originally Posted by 101RRS

Looks much the same as a 101 rear drive shaft - they are very steep but work OK. Remember the 101 is mid engined with the shorter 101 wheelbase.

Originally Posted by Homestar

Agree - the 101 is very similar if not worse than that. The front of the 101 is much worse.

Thanks guys. I've been suffering a major case of mid-build jitters over the last few days, wondering if I'd mucked up big time? Looks like I'm maybe not ripping everything out again....

If it becomes an issue - lower the rear gearbox mounts a tad and whip out the rear axle housing and rotate it up so the tailshaft goes straight into the rear diff rather than at an angle.

Easy peasy

I’ll crawl under the 101 tomorrow and measure the prop angles if you want - I had it out today but had put it away again by the time I read this.

Just having a read and max normal operating angles seem to commonly be based on length of shaft and operating RPM. Running some numbers on say 36” tyres and 4.11 diffs (not sure what yours are, just having a guess) then at 100KPH your prop shaft is spinning about 2,450RPM if I’ve done my math right which suggests a normal operating angle around 8 degrees but at 2,000RPM it’s around 10 degrees. Given a uni joint can operate at around 30 degrees I think 10 is absolutely fine for a vehicle like this.

Originally Posted by Homestar

I’ll crawl under the 101 tomorrow and measure the prop angles if you want - I had it out today but had put it away again by the time I read this.

It would be great if you could do that, whenever you got a chance to. Just to see if I'm in the right ballpark. I presume a 101 uses the same Hardy Spicer 1300 series unis as a "normal" LR?

Originally Posted by cjc_td5

It would be great if you could do that, whenever you got a chance to. Just to see if I'm in the right ballpark. I presume a 101 uses the same Hardy Spicer 1300 series unis as a "normal" LR?

I think so, but not 100% sure. I’ve got a custom unit in the front as the standard ones rumble something chronic on over run. Currently a double/single with larger unis it will soon be a double/double as Inhave another double carden joint for the other end now. This has reduced issues no end but I’m guessing this angle is much more severe that what you’re looking at.

Will get some pics and angles in the morning.