1968ragtop

I'm thinking of doing a 4 speed swap and wondering if its possible to go with a hydraulic clutch setup. I'm looking at either going with a muncie or a t-10. Thanks for any info.

jensenracing77

i know Mondello had a kit to do this many years ago. i figure they still offer one but they likely just purchased it from somewhere else and reselling them. it looked like a throwout bearing attached to a hydraulic lifter mechanism. i am sure there are kits out there.

it would sure make it easier to run headers on a 4 speed car with one.

joe_padavano

Many vendors sell hydraulic throwout bearings that can be used. Check Summit or Jegs. The Muncie is the same for Olds and Chevy, so you have a good selection. You'll obviously need to adapt a clutch master cylinder.

1968ragtop

Thanks for the info. The reason I'm asking is the 455 in my car is a newer block that does not have the threaded location needed to mount the z bar for clutch linkage. I figured this may be a way around that. Let me know if I am over looking something here, but it sounds doable!

1968ragtop

I bought a muncie m-20 4 speed. I'm wondering if the cross member from the 2 speed glide will work with the 4 speed? Just trying to figure out what other parts I'm going to need!

1968ragtop

heres some pics

gregvm

I installed a hyd. clutch setup in my '68, purchased from Keisler Engineering. They have a nice package with the release bearing, hose, and master cylinder, which make installation a snap. You'll just have to be careful with the line if you run headers. I've had mine for 3 years now...no problems, and shifts like a charm. ALOT smoother than that mechanical linkage

Yes, the cross member will work, you may have to move it to a different set of holes on the frame (there are several sets from the factory), however your driveshaft may not be the correct length, and you may have to change the parking brake cable length.

Hope this helps
Greg

1968ragtop

greg, thanks for the info, I'll look into that.

1968ragtop

I am getting my parts together to do the 4 speed swap. I need pressure plate bolts, does anyone have a part number for a kit from Mr gasket or arp? Thanks in advance

allyolds68

I don't know if you went ahead and bought the hydraulic clutch set up but if you're going to run a Muncie I'd save the money and tweak a bracket to work:


https://classicoldsmobile.com/forums...r-bracket.html


There are more threads like this too


The other issue you have is your crank probably isn't drilled for the input shaft on the tranny


edit:
I just realized this is like two years old. I don't have the bolt size but the pressure plate bolts will probably be the same length whether it's a Olds, Pontiac, Buick or Chevy application


edit again:


From a quick search here:

1968ragtop

I just ordered the hyd. clutch today so I might as well go with it. Thanks for the info on the bolts, most of my parts are being shipped now hope they get here soon!

RetroRanger

keep us unpdated i would like to swap to a manual trans someday sooner rather than later

is your crank drilled for a manual trans? if not what is your plan w it ?

1968ragtop

My enjine builder at the time said the crank was drilled, should be good there. I've been doing some reading and have a few questions.
1. steering column support, can I just cut a hole in my factory piece?
2.nuetral safety switch goes on the clutch pedal, where to get these parts?
3.reverse light switch, where is this mounted, where to get these parts?
4. reverse lock out rods and bracket, what is this for, where do I get these parts?
Thanks again guys

1968ragtop

Reverse lockout seems to be 69 and newer, not on my 68. I'm guessing its an interlock with the steering column?

joe_padavano

It's technically not a "reverse lockout", it's a shifter lock that prevents the shifter from moving if the steering column is locked. The shifter lock was part of the federally-mandated locking steering column that was required staring in the 1969 model year.

1968ragtop

Thanks Joe. So the neutral safety switch goes on the clutch pedal? Where is the reverse light switch mounted?

joe_padavano

Yes, the NSS pigtail plugs into the clutch safety switch. The backup light switch mounts to the trans and is actuated by a small link to the reverse arm on the trans. This photo is from a Chebby, but you get the idea:

allyolds68

OK Joe, I'm stumped. I never installed any clutch safety switch in my 68 because I could never find it in the assembly manual. I've been back through sections 7 and 12 and I still can't find it. I found the jumper to eliminate the column neutral safety (used in the column shift automatic) on page 12-111 but can't find any reference to the clutch switch.


(sorry for the hijack)


edit:


I know someone just started to chime in...I know there was no backdrive lockout in 68, but was there a neutral safety requiring the clutch to be depressed????

1968ragtop

Thanks Joe for the info. If someone has pics of the N.S.S. pigtail and the clutch safety switch that would be great! Thanks

1968ragtop

I have been considering changing my gear ratio more for highway cruising. Any recommendations. I currently have 3.55 gears. What is a good ratio to run with an M-20 4 speed?

allyolds68

I have 3.42's and an M20 and I wouldn't go lower than 3.08's. I had 2.93's when I got the car and it bogged off the line. Personally I'd stay with the 3.55's

1968ragtop

3.55 is a nice gear, but the rpm is a little high on the hiway. I was thinking of a 3.08 gear, I wouldn't go any taller than 3.08. I've never driven a car with an M-20 so I don't know what the gear spacing is like and what works well with this trans. I am also running 27" tall tires currently.

allyolds68

I'm running a 26.6" tall tire. Factory rears with an M20 were 3.08, 3.23, & 3.42. I'm sure the 3.08 will be the best option for what you're looking for

1968ragtop

allyolds, thanks for the info. I'm thinking 3.08 but would also consider 3.23

garys 68&72

Depends on your motor too. I had a Muncie with a 3.08 rear in my vette, but a big cam on a relatively low compression motor. It was a real dog off the line.
Btw, where did you order your hydraulic clutch from?

dc2x4drvr

When I had my M20, the 3:08 was the best highway gear, and pulled good on the street..

1968ragtop

Thanks for the info guys. Gary, I ordered the hydraulic clutch from Summit. American Powertrain is the manufacturer.

gregvm

3.73 was also installed with an M20 I had two of them in 2 different 442's(both m20's) but they were Chebby 12 bolts.

I concur, 3.08 is your best route with 26.6 tire.
Greg

allyolds68

The 68 assembly manual doesn't show 3.73's available with the M20 only the M21

1968ragtop

2 more rookie questions. I ordered a "doorman" pilot bushing off fleabay are they any good quality wise? Other question, do I need to get new carpet for the 4 speed (I'm not using a console) Thanks

dc2x4drvr

The best (OEM) pilot bearing for a stock Olds 4 Speed crank is a BCA # 7109, your local bearing house can source for you..

1968ragtop

Thanks, I'll look into that

1968ragtop

I am doing some mock up to see what parts I may still need. It turns out I need a 4 speed fly wheel, the one I had is Not the correct one. Where is the best place to get a quality 4 speed flywheel. Looking for quality and price. Thanks

1968ragtop

The Parts Place has a new manual transmission flywheel for my car for $279 Decent price I think. Is this a decent quality piece?

allyolds68

Here's a used marine flywheel. Resurface it and go. I wouldn't spend the extra money unless you want SFI and that will probably be more than $279 for a good one


http://www.ebay.com/itm/Oldsmobile-3...e74f57&vxp=mtr


Summit also has flywheels starting at about $330 including shipping.

1968ragtop

Thanks allyolds, I bought an original olds flywheel off of ebay in mint shape and already resurfaced. Should do the trick!

1968ragtop

I am in the middle of the 4 speed swap and have a few questions on the clutch. I can do a hydraulic clutch or a factory mechanical linkage clutch. Is there enough room for either set up with the factory power brake booster? Or will I need to go with manual brakes (no booster)? Thanks

joe_padavano

A whole lot of cars came from the factory with a manual trans and power brakes, so yeah, I think it will clear just fine.

oldsmobiledave

True but in 1972 the ONLY Muncie available was the M-20. If your Cutlass had the W-29 & the W-30 options and a stick you got 3.42s as standard equipment with 3.73s optional.


That is how my 1972 "Cutlass" is optioned.

1968ragtop

Thanks guys, after looking a little closer, I think the master cylinder will fit under the booster, not a lot of room to spare but should fit.