teardown questions

[saabfan9]

hey guys tearing the '73 down i'm starting to get skeered anyway since i'm in this deep i have a few questions: is a c900 5spd a direct bolt up no modifications? can anyone rec. a place that has a complete engine gasket teardown kit? anything else you guys might rec. since i'm in this deep? i know this is asking a lot but what about an engine harness? i see alot of spliced hacked up wiring that i'll have to sort out...thanks for any help chris

[Luke]

hey guys tearing the '73 down i'm starting to get skeered anyway since i'm in this deep i have a few questions: is a c900 5spd a direct bolt up no modifications? can anyone rec. a place that has a complete engine gasket teardown kit? anything else you guys might rec. since i'm in this deep? i know this is asking a lot but what about an engine harness? i see alot of spliced hacked up wiring that i'll have to sort out...thanks for any help chris

On the 5spd
A 5spd CAN be a direct bolt-in within no machining or cutting given the right parts, you'd need the front chain cover from a 1980 99 4spd. There is a "hump" on the bottom of the casting that is different that the 5 spd needs (see jordan pic below, the small protruding half moon at the very bottom). On a '73 you will also need to change the axles/CV's/Knuckles over to a 75 and later style (or ideally 81+ knuckles with 75-80 99 axles), as the axles are different lengths from 75 on accounting for a change in the bearings size of the differential.
You'd also need the plastic guide plate that bolts under the shifter housing from a 80-82 900 5spd, this plastic piece is shaped differently to allow for a gate for 5th gear.

So thats the 100% bolt in method using all un-modified parts, and keep all standard 99 motor mounts, etc.
Theres are also lots of options using custom made stuff or variations of later 900 stuff adapted to fit. Drew had a nice solution using a common turbo style 900 chain cover and a custom front motor mount.

On the gaskets
Maybe 90% of the gaskets can be replaced with loctite 518 anerobic gasket maker, I like to use a real intake manifold gasket, but everything else can pretty much be replaced with 518.

[Jordan]

hey guys tearing the '73 down i'm starting to get skeered anyway since i'm in this deep i have a few questions: is a c900 5spd a direct bolt up no modifications?

edit: lol Luke beat me too it.

can anyone rec. a place that has a complete engine gasket teardown kit?

What are you tearing down and why? Most of the gaskets main gaskets aren't too difficult to find, anything you can't find, use an anerobic sealer like loctite 518. Oil pump o-rings are a standard o-ring size. I might have a couple left over if you need one.

anything else you guys might rec. since i'm in this deep? i know this is asking a lot but what about an engine harness? i see alot of spliced hacked up wiring that i'll have to sort out...thanks for any help chris

No replacement harnesses are available aftermarket, but you should be able to repair it if you're having problems.

[Jordan]

On the gaskets
Maybe 90% of the gaskets can be replaced with loctite 518 anerobic gasket maker, I like to use a real intake manifold gasket, but everything else can pretty much be replaced with 518.

I like to use real head gaskets as well

[Luke]

On the gaskets
Maybe 90% of the gaskets can be replaced with loctite 518 anerobic gasket maker, I like to use a real intake manifold gasket, but everything else can pretty much be replaced with 518.

I like to use real head gaskets as well

You mean the one I cut out of leftover cork floor tiles with an exacto knife isnt going to hold up?

[Jordan]

On the gaskets
Maybe 90% of the gaskets can be replaced with loctite 518 anerobic gasket maker, I like to use a real intake manifold gasket, but everything else can pretty much be replaced with 518.

I like to use real head gaskets as well

You mean the one I cut out of leftover cork floor tiles with an exacto knife isnt going to hold up?

Knowing you, it probably would work.

Oh I deleted it in my first post, but does the standard clutch line to the slave reach? External vs annular?

[Luke]

Oh I deleted it in my first post, but does the standard clutch line to the slave reach? External vs annular?

Good point, nope I dont think it will and the master on the 73 is the vertical type, so a complete later hose can't be used... So I guess it can't actually be done 100% bolt in, a flaring tool will have to be used, a 1/4" inverted flare union could be used to graft the original line to the front end of a 900 one. Thats the case with the brake lines as well, since the 73 has english fittings, if going to later calipers, some sort of adapter lines will need to be made.

[Luke]

Also, I think its a good time to mention that its a slippery slope here... Depending on your intentions, if the car is basically running and driving, it may be advisable to just fix the small stuff and enjoy the car as is for a while... Gain some familiarity with the systems and mechanics of it. You may be well aware, but its really easy for these to snowball into 8 year restoration efforts where the car becomes more of a nuisance thats in the way than a fun car that you take out for errands on the weekends, run some auto-x with and just generally enjoy.
I'm no better than anyone else here at saying "when" but my '79 900 is probably the first "project" car that I didnt get totally carried away with, and I think its the one I've actually been able enjoy driving the most.

[paulh]

Oh I deleted it in my first post, but does the standard clutch line to the slave reach? External vs annular?

Good point, nope I dont think it will and the master on the 73 is the vertical type, so a complete later hose can't be used... So I guess it can't actually be done 100% bolt in, a flaring tool will have to be used, a 1/4" inverted flare union could be used to graft the original line to the front end of a 900 one. Thats the case with the brake lines as well, since the 73 has english fittings, if going to later calipers, some sort of adapter lines will need to be made.

Oddly enough I think 73 is a bit of a transition year for the english vs metric fittings, on my car at least the clutch master was in fact english, but the brake fittings at the body were metric.

Paul

[DrewP]

Yup, my '73 had inch fittings at the slave and at the brake cylinders, all Lockheed parts.

I briefly made a '78 4-speed work in my '73 when I first got it running without changing the axles/hubs/knuckles to the later style. I kept the '73 length halfshafts.

What I did was swap the diff and the inner driver bearing cups from the '73 into the '78. The ring gears are interchangeable, so keep the ring gear with the trans it goes to so it stays matched to the output pinion, but you will have to re-set the shim sets underneath the diff bearing cups to get the backlash on the ring gear correct.

I have a suspicion that this might work on a 5-speed also, but I haven't tried it. You'd have to figure out the front mount and the shifter linkage but you may be able to get away without having to change the axles and unsprung parts.

[saabfan9]

well now that idea is scrapped i have access to a '78 but that seems like a major undertaking early c900 stuff around here is very hard to come by ..i was hoping to make her a little more civil at 65 mph it's running 3500+ rpm's....and last night i discovered the evil that is the battery tray ground location i'll have to spend some time sorting and repairing alot of wiring she DID run and drive but now i'm nervious...i was planning on bringing her out to the SOC but now i might trailer for most of the trip or drive the aero instead...now it's time to locate a radiator found mine leaking and rotten at the bottom..i'll get some new picks up in the build section soon

[Luke]

Yup, my '73 had inch fittings at the slave and at the brake cylinders, all Lockheed parts.

I briefly made a '78 4-speed work in my '73 when I first got it running without changing the axles/hubs/knuckles to the later style. I kept the '73 length halfshafts.

What I did was swap the diff and the inner driver bearing cups from the '73 into the '78. The ring gears are interchangeable, so keep the ring gear with the trans it goes to so it stays matched to the output pinion, but you will have to re-set the shim sets underneath the diff bearing cups to get the backlash on the ring gear correct.

I have a suspicion that this might work on a 5-speed also, but I haven't tried it. You'd have to figure out the front mount and the shifter linkage but you may be able to get away without having to change the axles and unsprung parts.

Yeah good point Drew, it probably would work on a 5spd, but the bearings on the early diff are way dinky and it prob wouldnt be a good idea for a high power setup.

[99Super]

Hey! That trans pic looks familiar...
When I installed the 5-speed in my 74, I had the same issue w/ the clutch line. I used the short steel slave section from a 900, the long section from the stock MC and had my local hydraulics shop crimp on a new flexible section to connect the two.

When I still had my old '73 (my first 99) I always thought the engine was a bit buzzy at 65+ but didn't worry about it as it had no tach. Maybe just delete the tach???


john

[DrewP]

I just slid a piece of hose onto the metal clutch line from a C900 and hose clamped it on, drove it like that for a week or so, I think it's still assembled somewhere and hasn't started leaking....

[Neil_G]

A 5spd CAN be a direct bolt-in within no machining or cutting given the right parts, you'd need the front chain cover from a 1980 99 4spd. There is a "hump" on the bottom of the casting that is different that the 5 spd needs (see jordan pic below, the small protruding half moon at the very bottom).

Is it an easy job to add a hump to a non-hump 99 front cover?
I had a look at my cover last night and discovered it is a non-hump one.

regards
Neil