VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 1948 Stylemaster Coupe Questions

Hi all,

I just acquired a 1948 Stylemaster Coupe (216) at the end of last year. Love the car but I have a few problems/questions. I'm getting ready to pull it out of winter storage and want to get into some fixes. Any thoughts would be appreciated:

1. I get a lot of blow-by from the valve cover vents and draft tube. In fact, we have to ride with the windows partially down because the oil smoke comes into the passenger compartment. Should I be considering a PCV system, or could something else be going on here?

2. I need to replace the fan belt, but can't get it off between the radiator and fan. Any thoughts on why the gap is so small? Could it be motor mounts?

3. How would I know if the vacuum shift assist isn't working? The car grinds almost always from 1st to 2nd even when I double clutch. Can the vacuum be repaired? Where should I look for vacuum leaks? Any typical areas?

Thanks for your thoughts. This is a great forum!

Smoke???Thats not good and certainly not normal....What do you know about the previous owner and what was done to your engine?is it stock??The radiator/fan clearence is strange ??use the shop manual to adjust your vacumm asist,if all your linkage and vacumm asist is working properly you should have no grinding..If the vacumm asist is not working at all it will be extremly hard to shift

#1
The excessive blow-by is caused by worn cylinder walls, worn compression rings or stuck rings (or a hole in a piston)
The first thing I would do is remove the spark plugs, pour about 4 OZ of Marvel Mystery oil, SeaFoam or ATF in each cylinder and let soak for a couple of days
Of it dosen't help the engines needs rings or a rebuild. Sounds like more blow-by than a PC system could carry.

#2
Could be motor mounts or ?? Should be enough room to squeeze in.
Hard to tell without seeing it.

#3
If the vaccum shift is working the shift lever should move form gear to gear very easily with the engine runnning and very much effort when not running
First I would check to see if the vac.shift was removed and replaced by a conversion kit.
The vac. shift has nothing to do with gear grinding (except it was hard on the 2/3 syncro)
That is probably a transmission problem and the syncronizer drum needs replacing.

Rick:
I've got a 48 Fleetmaster, and, been through some of the same problems you've got. The engine/transmission mounts could indeed be the fan clearance problem. These cars have 5 rubber mounts - 2 under the front of the engine, 2 on the sides of the bell housing that serve to limit engine side to side movement, and 1 under the transmission that limits engine/transmission fore and aft movement. My suggestion on the tranny grinding problem - Make sure the linkage doesn't have excessive slop in it (bushings shot, etc.), adjust it and the vacuum shifter by the book, and, put heavier 85-140 gear lube in the tranny. The vacuum shifter on my car was shot, and, leaking vacuum badly. I replaced it with a conversion kit.

Regards:
Oldengineer

Could the bad motor mounts also contribute to grinding / shift problems due to alignment issues?

Don't worry the motor mounts are cheap and easy to replace with an afternoon, some hand tools and a jack. I would start there, and that would also allow you to get the fan belt swapped out. Maybe clear up the trans stuff too.

The smoke is as Gene said, most likely worn rings but maybe you can get by for a bit before tearing it down. I'd crack open that cowl vent and get some fresh air while you drive to help with ventilation

Good luck and don't get discouraged with your new purchase. We're happy to help with anything you need and you should be able to enjoy that Chevy for miles to come. Keep in touch.

chef-chevy

Thanks. The previous owner was very meticulous (or so I thought) by how it was kept and serviced. All records, etc. the car is very clean.

Will do on the shop manual - again thank you!

Chev Nut,

Thank you for the info. I'll try the MMO and hopefully it won't be anything more. It does sit for a while between shows and certainly over the winter so it may jest need a good MMO soak!

Oldengineer,

Excellent. Yes, I'll do all the engine mounts as soon as I can dig out the garage from all this snow! Also, good suggestions of the linkage and vacuum assist. Thanks.

Thanks Daryl Scott,

I'm the son of an old Chevy Ace Mechanic (back in the 50's) so I don't discourage easily, but the wife has her doubts on this one. I'm setting out to prove her wrong.

Good point on the motor mounts possibly adding to the shifting problems as well. Now I'm psyched to get the car out and get it fixed up. By the way, here's a photo of "Dr. Chester Detroit" -

[img]https://fbcdn-sphotos-g-a.akamaihd....3687340_68525d7370b6069b45ca8299b4b7820e[/img]

Good looking car, but how did Dr Chester Detroit get his name ?

Daryl & Rick:

RE: Engine mounts - When I acquired my 48, it was missing the two mounts on the sides of the bellhousing, and the mount under the tranny was rotten. My car was difficult to get going from a stop with out violent hopping, about a third of the time I couldn't get her to do a 2 - 3 upshift (much grinding because car was trying to go into reverse), and car frequently jumped out of third at speed. I also remembered that I had a brief problem with oil smell coming into the cabin. Turned out my oil fill cap wasn't sealing well. I replaced it with a NOS one with an intact gasket that actually snugged down good, and, that solved the problem.

Regards:
Oldengineer

Oldengineer, that's helpful. ONce you installed the new mounts did the shifting firm up? Hope so.

Lovely picture of "Chester Detroit" and I love the name, too. The car looks pretty regal in the two-tone. Best of luck with it this year.

Great thoughts - everybody! Thank you. I'll try all of it!

He got his name by combining one of my favorite movies, "Dr. Detroit" with the given name from his previous owner, Chester. On the way home, we took a little detour and wound up in front of a Dr.'s office on "Chester Street"!

I've ordered the 5 mounts and will hopefully be able to get the car into the "working garage" soon (too much snow).

Does anyone have any tips, tricks, or techniques for replacing them? I also have the shop manual on it's way, but if there any other hints, I'll take 'em.

Thank you.

Daryl: Yes - replacing the mounts helped. It got rid of all the jumping when starting out in 1st gear. To totally fix the up shift problem, I had to replace the bottom lever at the base of the steering column - the old one was bent and kept jumping out of the track in the upper lever. I also put new bushings on the levers going to the tranny and got rid of all the slop in the linkages. My car will still jump out of 3rd occasionally - and I think I stil have an issue with the swivel on the end of the tranny. Looks to me likes its glued in with Rtv.

Regards:
Oldengineer

Rick:

Just a heads up - there are 2 versions of the tranny mount. The original version has a metal plate bonded on top of it that goes up against the bottom of the tranny. The revised. Version doesn't have a metal plate on top. The original was bolted to the tranny bottom using. 2 studs going down thru the mount. The revised one used 2 bolts and washers going up thru the mount into the tranny where the studs originally were. If using the newer design, be careful with the bolts and washers to make sure things snug down ok. If bolts are a little too long, you'll be able to spin the washers under the bolt heads with your fingers. Luckily, my car had the old style mount, but, the studs had been replaced with bolts. I used my floor jack under the tranny and raised it enough to slip the old mount out, and, put the new one in. My front engine mounts were ok - so can't advise you on changing them. Do the side mounts by the book - I'm assuming your car uses the M style side mounts like my 48 does. The M style side mount was an improvement that as made as well over an earlier design.
Regards:
Oldengineer

Lots of great info...Love your car by the way...Noticed your door handle isn't sagging...Typical of cars that age, on the drivers side...How about the engine block color...? Lots of rebuildt blocks back in the day were left light blue...Wondered how old the paint job is...Could be lacquer...Kept it out of the sun as much as possible and keep a good wax job on it...!