5 speed conversion questions

[Scott]

Hi all,

I'm very tempted to stick a 5 speed in my 74 99, and I understand you need a late model 99 front mount to make it plug and play. What year front mount is needed to make this possible? Does anyone know of any available for a Saab nut on a tight budget? :)

I have read a few conversion stories, but I haven't noticed an answer to which shifter is needed to make this work. Can you use the 99 shifter or do you have to transplant a 5 speed shifter? I'd much prefer to keep the old one, but I don't know if it will work.

Thanks!

[Geoff]

you need a 4spd cover from an '80 or later 99 or 900. Since the last year for 99s in the US is 1980 and the last year for 4spds in a 900 is 1980... I think you get the picture. The other thing you could do would be to weld a little bung in the right spot on an earlier chain driven 99 4spd front cover. This will keep fluid from leaking out.

Shifter: You need to do more than just a shifter. The bottom plastic gate under the shift housing limits the shifter's movement. You need one from a 5spd. A 5spd shifter shaft might be necessary too since they have a little kink in them to help get all gears. There are different ways to do it. When I put a 5spd into my '76 I used the shifter, 5spd plastic gate, self-centering spring mechanism, and shift shaft from a 1980 900 with a 5spd. The early 900s had a bunch of 99 compatible parts. Everything dropped right in and almost. The only thing I had to do was to drill out the rear mount for the shifter housing so I could turn the shift housing a few degrees clockwise. I looked at the 900 I pulled the parts out of and the shift housing mounts were welded to the body of the car a little off-center so that when it was bolted down it would point a few degrees clockwise instead of forward.

The issue with changing shift shafts is that the bottom ball for the shifter changed size through the years (3 times) which means the ring in the shift shaft changed size. I can't remember if the bottom ball is interchangeable between different shifters. I imagine that it is and you could use whatever shifter in your car you wanted so long as the correct size lower ball mates with the shift shaft you have.

[Scott]

Not as plug and play as I would have hoped...

Any elaboration on what would have to be done to make an older one work?

Speaking of leaking, I recall I had a problem with some leaking out the front on the 4 speed...

Thanks

[Geoff]

early or late 5spd should be nearly identical for putting in the car. Up to mid year '86 the centering mechanism was attached to the shifter housing. After that they were internal to the transmission. Early 5spds had the smaller inner drivers that a 99 had. Later 5spds (starting '85 turbos, '86 all I think) had larger inner drivers. You can swap smaller ones in to a later transmission to fit up to your driveshafts.

[saabfan9]

would like an extra gear as well....so i need to find an 85 or older donor car (80-81 ideal) are the spindles useable from my 99? i'm not sure about the mount part for the front cover (also i do not know how to weld or have a welder)...is this a do-able task until i find this rare cover? pics of what i need to look for on the cover?

[Geoff]

80-81 probably isn't ideal because as the years went on the transmissions got stronger. You could use any transmission but you'd need the '85 and earlier inner drivers. But... the drivers on your transmission might fit a 5spd anyway. I can't remember what the earlier cars have for inner drivers but I know some very early 99s have two rollers (bipod joints?) vs. three sets of rollers (tripod joints) on the drive shafts and corresponding matching inner drivers. All the 99s I've had were '75 and newer and all had even newer (chain driven) transmissions. I know that at least those transmissions can swap inner drivers with a 5spd.

The bump at the bottom of the transmission cover looks like this

Humpty Dance

The first time I put a 5spd into my car I didn't have the right transmission cover so I took the stock 5spd cover, laid it on top of some plastic on a bench and packed some modeling clay around the bump. Then I cleaned and gouged the non-bumped 4spd cover where the bump would be. Then I removed the 5spd cover from the bench and slipped the 4spd cover into the same spot, using the modeling clay as a mold. I filled the mold with JB Weld and then block sanded it flat on the gasket surface. I didn't do a great job and it weeped a little but not bad. It held up for at least one very rough rally.

[DrewP]

I put a 5-speed in my '73. It had tripod inner joints, I believe I swapped the diff housing, inner drivers, and inner driver bearing flanges from the '73 onto the 5-speed either because the offsets were different, or because the tripods were the wrong size. I forget which, but a visual mix-and-match with the two of them sitting next to each other should tell you what you need to do.