Smooth case gearbox in early MKII Sprite?

[Millrat]

My question is this: Would my early MKII (HAN6L791) Sprite come with a smoth case gearbox? Engine is #9CG-U-H301. The current gearbox was replaced in 1983 but only has about 50 miles on it and appears to be ribbed. I seem to have some bugeye crossover parts.

 

[Billm]

The Spridget had smooth cases until the 1100 came along, around mid '63? I had several of them with smooth cases and 948's.
BillM

 

[Millrat]

So that would be consistent with the "U" in the engine code? The engine in mine was painted red sometime before 1983 so I am not sure what was done or when. Trying to determine if it is original (likely) or not.

 

[Billm]

"U" just means "center change gearbox". I don't have a clue what THAT means but that is isn't a "close ratio gearbox".
BillM

 

[Jim_Gruber]

The '66 1098 that got transplanted into Bugsy my '68 Sprite came with a smooth case gearbox.

 

[Billm]

That smoothcase had to be ground out a bit for the 1098 pressure plate to fit- other than that it probably worked OK
BillM

 

[Deleted member 3254]

Any one have the same setup?

I have a 1959 AH Sprite with a rebuilt 1275 engine, a 948 transmission and a clutch that does not fully disengage. Previous advice I had received about 3 years ago stated I should use a 1275 clutch with the original 948 clutch fork (looks to be in good shape, replaced bushing) and a slightly longer slave cylinder rod (I cut down a 1275 rod - don't remember dimension, but will check). The 948 transmission was working fine with the original 948 engine (which died about 5 years ago).
I ordered and installed a 3 in 1 (pressure plate, disc, and release bearing) clutch kit for 1275. Unfortunately in my zeal I managed to install the disc backwards and the slave cylinder was unable to move the fork at all. Took it apart again, corrected disc position and filled with hope got it all put together again, bled the slave (I'm using silicone DOT 5), and was able to see the fork move (about 7/16") when the clutch pedal was depressed. With the engine running I'm unable to shift into 2nd thru 4th gear without grinding. I've not driven it at all, just tested it with it on stands, I've bled the clutch system at least 3 more times with no change.
Has anyone got any advice or been in the situation I'm currently in? I've lately seen some older posts in my searches that suggest one should use a clutch kit to match the transmission as the 1275 release bearing is different from the 948 (thicker/thinner?) I'm hesitant to go thru the teardown again until I'm more certain of the solution. Don't mind ordering another 948 clutch kit and slave rod if that's what it will take to get on the road again - it's been too long and I'm not getting any younger or smarter!

 

[Deleted member 8987]

Re: Any one have the same setup?

Don't recall the fittment specs....but sometimes if you install the disc backwards, the extended hub hits the fly to crank bolt heads, and when you tighten the pressure plate, it warps the web and Marcel between the faces.
Makes it seem like you've got a big adjustment issue.

Then, you add in fuzz......you may never get it to work right up on stands.
The fuzz on the face of the friction material needs to be worked off under load.

Then, did I read correctly....the gears grind in 2, 3 and 4?

First is non-synchro, on a smoothside, right? And if the engine is running, and you can get it into first, the issue is not the clutch disengaging.

2, 3 and 4 have synchros....if it grinds, the trans needs work.
Or oil.

 

[Gerard]

Re: Any one have the same setup?

I have a 1959 AH Sprite with a rebuilt 1275 engine, a 948 transmission and a clutch that does not fully disengage.

Charlie,

What engine back plate did you use; the 948 stamped steel one or the 1275 cast steel one? I'm assuming you used the 1275 flywheel? Did you replace the pilot bush or bearing?

One of these days, I'l have to measure the cumulative differences between clutch combinations, but I can tell you that the depth of the pilot hole in the 1275 crankshaft is considerably less than the 948/1098. (2-1/8" vs 1-3/8") It might be possible you could be bottoming out keeping the first motion turning when the clutch is in.

 

[Deleted member 3254]

Re: Any one have the same setup?

Sorry, wasn't clear - it grinds in all gears. Since first and reverse are non-synchro in the smoothcase I expected that though. Thanks for your info. Hadn't thought about warping or fuzz. More work is in my future...

 

[Deleted member 3254]

Re: Any one have the same setup?

I used the 1275 cast steel back plate and the 1275 flywheel. I just visited Gerards garage website (is that you?) - saw the pics of the throw out bearing differences. Your thoughts are appreciated. I first tried a 1275 fork, but I was unable to get it fitted correctly. I did replace the pilot bush/bearing also.
Another tear down is in my future.....

 

[Gerard]

Re: Any one have the same setup?

I used the 1275 cast steel back plate and the 1275 flywheel. I just visited Gerards garage website (is that you?) - saw the pics of the throw out bearing differences. Your thoughts are appreciated. I first tried a 1275 fork, but I was unable to get it fitted correctly. I did replace the pilot bush/bearing also.
Another tear down is in my future.....

Yep, that's me. OK, well, sounds like you did stuff right. I think the next thing to do is look at your pushrod adjustment at the pedal box. A few turns of the rod will make a lot of difference.


If that doesn't cure it, I think you might see about using a fork and front cover from a ribcase or just use a ribcase instead. There pretty plentiful and I have several in good shape or if you need one rebuilt.

 

[Billm]

Re: Any one have the same setup?

It is possible (but not probably) that when you put in the clutch disk backwards you may have bent (bell shape)the disk and that could (probably not) cause the problem that you are seeing.
Nest time that you have the disk out hold it up against a straightedge to see if it is flat.
BillM

 

[Deleted member 8987]

Re: Any one have the same setup?

Yeah, I said that......but also, lat the disc on the flywheel, one side first, hold opposite edges with your fingers.thumbs, press down on one side, see if it "rocks" down to lay on the flywheel surface, then flip it over and try it. If the re is clearance on one side to do that, you've warped it.

 

[Billm]

Re: Any one have the same setup?

I thought that is what you meant Dave- just verifying
Bill

 

[Deleted member 8987]

Re: Any one have the same setup?

I've seen warped discs before. Fun trying to get them to work.

 

[Deleted member 3254]

Re: Any one have the same setup?

Thanks for the advice. Sorry I couldn't get back sooner - called away for grandchild sitting and an elderly parent emergency. I verified that I did indeed order and install a 3 in 1 clutch kit for a 1275 - will use borescope today to visually check release bearing is correct one. I'm 100% certain I used 948 fork - in my spare parts I have a 1275 fork in original package (should have returned it, but didn't). Also the length of slave rod I had installed was 2.5" (center hole to end - for a 948) I also have a 1275 slave rod which is 2 11/16" (center hole to end). I'm wondering if the slave rode length has to match the engine/clutch or the transmission - now suspicious that may be the problem. Any advice on that thought? Master and Slave cylinder replaced in original teardown. Another teardown is my last resort.
Thanks again.

 

[smaceng]

Re: Any one have the same setup?

I like to check and double check when it comes to big risk actions, like puting in the trans and engine and not being sure if the trans is hooked up correctly....sort of your situation. First time I put my BE together, I set up my engine and trans and used a long line to the clutch master to actuate the slave cylinder. That allowed me to verify that the trans would go into all the gears and that it was free to spin in neutral. Just a thought.
Scott in CA

 

[Jim_Gruber]

Re: Any one have the same setup?

SO trying out the longer pushrod seems like a possible simple solution. Gerard might be able to weigh in here on this subject. IF it seems like clutch is not disengaging fully, changing to the longer pushrod seems logical. The mix and match of different components seems to be a challenge. I believe I did need to go to a longer pushrod in using my smoothcase and 1098 with a '68 1275 Slave. BTW I needed to modify the case on the smoothcase so the clutch slave aligned properly. An interesting engineering challenge with an angle grinder from below with engine and tranny in the car. Mounting the 1275 Slave, it came in at the wrong angle and tranny case needed to be ground down to align properly. I made it work and it's been working successfully for the last 12 years.

Could be a risk of over extending and bending the clutch fork but difference in pushrod length is not all that different.It doesn't sound like it works the way things are set up now.

 

[Gerard]

I can't really comment on the smooth case/1275 combo as I've never tried that, only the other way around. I know for certain that the smoothcase uses a different fork and front cover and that the geometry is very different. The correct thing would probably be to use the later front cover and fork with the matching pushrod and throw out bearing. Also, there is always the possibility that the fork is bent from being over driven. As I mentioned in the previous post, I would try adjusting the pushrod at the pedal box if all else checks out.

Here's a pic of one that is bent. Unless you compare to a normal one, you might never realize this. These are both the same part number (ribcase 1098-1275)