TheSamba.com :: View topic - Bus needs new transmission 091, 5rib, or side shift 091?

Wed Jun 27, 2018 1:42 am

Hey guys

Ive been out of the loop a few years sonexcuse my ignorance

My bus needs a new trans i think... Last time I drove it it was making funny noise from the trans and a clunk started new just before ibparked it last year.

Im away from home and on a cell phone browser so researching is painful. But i did read the entire transmission for dummies thread in the off raod fourm

I have a line on a side shift 091 in my town, but that tran thread has led me to believe the swap to nose shift is a nasty job requiring full disassembly of the transmission... Im not gonna do that if thats the case, anyone have person experience with this swap?

I have a line on a used 091 for 650$ but requires a little shipping, but it is in canada at least.

Last option, i have a spare 5rib. Are the ratios close enough to make this unit a suitable candidate to run with my engine? Its a raby CS 2L. A little extra fan speed and maybe a bit slower final drive wont hurt my feelings, but is the difference between the 5 rib and the 091 too much? Again anyone with personal experience, would i be happier spending the money on the 091 and shipping?

I spent my lifes savings $ travelling the last 3 years so if the difference between the 091 and 5 rib is livable....

Thanks everyone. Missed this place. :)

Wed Jun 27, 2018 4:16 am

.NOrmal 091 would be my choice.

Wed Jun 27, 2018 4:44 am

Get a good rebuild done today while the parts are still available.

Wed Jun 27, 2018 6:23 am

I did some looking once and found the differences between a 5 and 6 rib to be minimal. If you have a good five rib, use it.

Wed Jun 27, 2018 6:59 am

with a 2L engine an 091 would be best. The final drive is a better ratio for the 2L engine.

Buying an 091 outright you may get as many problems as what you have. Might consider having yours rebuilt.

Wed Jun 27, 2018 7:03 am

From off the top of my head and going back several years I'm pretty sure it's about a 200 rpm difference at 65 mph. Now, I do not know if there are other concerns besides ratios like strength. I know that the 091 is much stronger than the 002 for instance.

For 200 rpm, given that you say you already have a good 5 rib it seems like an easy decision to make.

Wed Jun 27, 2018 7:39 am

I ran a stock 2L on the 5 rib in my '75 for years, never any drivability issues. If you've already got the 5 rib I wouldn't be afraid to use it.

Swap the bellhousing and input shaft from your existing transmission so you can use your existing clutch, and I think there *might* be a difference in the forward shift linkage but don't know for sure.

Wed Jun 27, 2018 9:12 am

What if your funny noise/ clunk is a stripping out hub or a bad CV?

Wed Jun 27, 2018 12:17 pm

X2^^^
Grab the CV shaft and give it a shake. Is one of the CV's loose?
Before it gets this bad. They will clunk. Pull the hub caps. Look for movement in the nut in forward and reverse.
https://m.youtube.com/watch?v=ZIHPGoV5PyM

The 1974-75 is the 5 rib.

Wed Jun 27, 2018 12:22 pm

well thing is about the whrring whiny noise is that its in all but 4th gear, which makes me feel its in the trans. it was a used trans and i swapped in fancy new synthetic oil so perhaps that accelerated the demise of some internals

ill double check the cvs but the clunk felt like a bit of a slip before a dull thudddish clunk, usually when switching gears, even at speed (if i remember correctly)

Wed Jun 27, 2018 1:29 pm

rustbus wrote: well thing is about the whrring whiny noise is that its in all but 4th gear, which makes me feel its in the trans. it was a used trans and i swapped in fancy new synthetic oil so perhaps that accelerated the demise of some internals

ill double check the cvs but the clunk felt like a bit of a slip before a dull thudddish clunk, usually when switching gears, even at speed (if i remember correctly)

Check your mount too. not saying it's NOT the trans, but it'd be a shame to replace it and miss something simple.

Wed Jun 27, 2018 2:42 pm

Were it me:

If I wanted to drive the bus sooner rather than later, I would first verify things like mounts and CVs as mentioned and then swap in your 5rib.

See how you like that. If you hate it, then have the current noisy 091 rebuilt.

If it were a $100 used 091, I think it would be worth the gamble of the work of cleaning and new gaskets to see if it'll work. (I actually did this and was lucky with my '73. Seller didn't know the internal condition so I bought it as a possible core.) But it seems to me that $650 is close enough to the cost of a fresh stock rebuild that I'd spend that money on having the current one redone.

Wed Jun 27, 2018 5:04 pm

Rebuild is closer to $1k

Wed Jun 27, 2018 5:50 pm

aeromech wrote: Rebuild is closer to $1k

I said "close enough" :)

I think I would still rather spend a grand on getting a known rebuilt trans than $650 on an unknown one.

So I say throw in the 5-rib for summer driving fun and prepare to have the other rebuilt.

Wed Jun 27, 2018 6:21 pm

I agree with dat

Wed Jun 27, 2018 10:15 pm

thanks for the support and suggestions. ill be home soon and get that 5 rib going. i think ill stick with dino oil this time... :)

Thu Jun 28, 2018 8:22 am

If the synthetic gear oil was not a GL-4, that could be your problem. It may be too slippery, not allowing the gears to brake so the operating sleeve can slide in without crashing.
If there is no metal bits in the oil. It would be worth a try, to change the gear oil. Or add a friction modifier.

Good luck
Tcash