73 Grand Am Conversion to 4 speed

by vegadan Thu Jun 05, 2014 1:06 am

Hi All,

I don't post much (mainly a lurker), but as the topic title says, I converted my 73 Grand Am from auto to stick. I used the conversion kit from the Parts Place and it went ok for the most part. The problem I have now is that the clutch pedal effort seems high. The motor is a stock 400 with a 4 barrel and dual exhaust. It's no powerhouse, so I just bought a generic clutch kit from the local parts store. But looking at the clutch linkage arrangement, I am wondering if I did something wrong. From pictures that I have seen online of other installations, I think my z-bar is crooked. I believe that I installed it correctly, but I plan to double check that this weekend. I was hoping to find somebody in the Chicagoland area with a 4 speed car that I might be able to "compare notes" with. If anybody is in the area, please post here or shoot me a PM when it would be most convenient for us to meet. It could be at my place or yours, which ever is easiest for you. Thanks for the help.

Dan

by Pontichev327 Thu Jun 05, 2014 1:15 am

Love your car Dan! I have never driven a 4 speed G3 car, but some friends in the Pontiac club i'm in said their 74 GA factory 4 speed used up a lot of clutches. And that was from someone who also has a 66 GTO and a 70 Lemans, both 4 speeds. I'm not sure why. There are several peopl with Chevelle 4 speeds here, maybe they will know more.

by Joe73 Thu Jun 05, 2014 6:07 am

My ss is.a.factory 4 spd. If you post up some.pics Ill take a look to see.if.tbere is anything unusual. No.reason it should.be eating clutches. Do you have at least an inch of.freeplay at the.pedal? Is your pressure plate a tbree finger borg and beck or a standard diaphram? On a side note, what did you use for.the boot coming oug of the.firewall tbat the pusbrod.goes.through?

by vegadan Sat Jun 07, 2014 9:04 am

Thanks guys. The clutch is a standard diaphragm spring clutch from Perfection (I think they make Zoom clutches?). I'll try to get some pics today. It's hard to say if I have an inch free play at the pedal cause I don't have a clutch pedal bumper stop just yet. I couldn't find a reproduction one, but I researched online and found that a 59-63 Vette bumper looks close so we'll see how it works when I get it. As far as the clutch rod boot, I used a 2nd gen Camaro/Firebird boot. Somebody over at the A-body forum said that it was a close match and it worked out pretty well.

by Joe73 Sat Jun 07, 2014 6:27 pm

Yes, the second gen boot is very close except that its substantially smaller in overall size. It would work fine for a conversion, but since my firewall hole is factory, the camaro boot wont cover.

by vegadan Mon Jun 16, 2014 11:29 pm

Does anybody know if the clutch pedal pushrod bushing (not the main pedal bushing) is reproduced? Or will one for a 1972 Lemans/GTO work? And how important is the clutch fork boot? The new one I bought seems pretty stiff and may actually be pressing on the clutch fork forcing the release bearing to remain in constant contact with the clutch friction plate. Thanks, Dan.

by Joe73 Tue Jun 17, 2014 6:03 am

Dont know about the.bushing but Ive run without the boot for.quite awhile. The boot protects from water and some dirt from entering the clutch area.

by vegadan Mon Mar 16, 2015 11:14 pm

I have a question-I had my car out this weekend and the clutch effort is higher than I would like. I was thinking of modifying the arms on the z-bar to make them longer to help reduce the clutch effort. Has anybody ever done this? How about increasing the length of the clutch fork or use a fork that is longer than stock? Or I would be interested in any other suggestions.

Thanks,
Dan

by Joe73 Tue Mar 17, 2015 6:17 am

Are you running a diaphram or three finger pressure plate? Brand ? What pound pressure?

by vegadan Wed Mar 18, 2015 9:16 pm

Joe,

It's a standard diaphragm spring clutch from Perfection (I think they make Zoom clutches). I've tried to find the pound pressure but have had no luck. This is the clutch that I bought:

http://www.summitracing.com/parts/zzz-mu1675-1/overview/year/1973/make/pontiac/model/lemans

by Joe73 Wed Mar 18, 2015 10:05 pm

That clutch should be REAL easy on your foot. Can you post some pics from different angles as what your linkage, z bar, clutch fork look like?

Also, any chance your pushrod from your pedal to the Z bar is rubbing on the firewall? Reason I ask is because the first thing that comes to mind is that a factory 4 speed hole in the firewall is quite large. The camaro boot doesnt even come close to covering it. So to use the camaro boot, you have to make a substantially smaller hole in the firewall. So with the geometry of it I think you might rubbing may be an issue. Just an idea since all the rest of the linkage is just a bolt in.

I've done clutches on these G3s more times than I car to count.

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73 Grand Am Conversion to 4 speed

73 Grand Am Conversion to 4 speed

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Re: 73 Grand Am Conversion to 4 speed

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Re: 73 Grand Am Conversion to 4 speed

Re: 73 Grand Am Conversion to 4 speed

Re: 73 Grand Am Conversion to 4 speed

Re: 73 Grand Am Conversion to 4 speed