INFAMOUS SLIM JIMS

[Guest]

Anyone want to comment about the 1961-1964 Olds slim jim transmissions? If I remember right, there is a place in Port Clinton OH that rebuilds them, and even said they have seen them in race cars, and in some ways was better ( Quicker ) than the 4 speed Hydros. Anyone old enough to know the answer on that?

[rocketraider]

@#$%^&*!!! Howzat for comment?! <img src="http://www.aaca.org/ubbthreads/images/graemlins/laugh.gif" alt="" />

I'd love to find someone within a couple hundred miles who can rebuild one and not take an arm and leg in exchange for the work.

I've heard some folks say one properly set up can hang with an old 4-speed Hydro, but as quirky as the things are to adjust and with that outrageous 1-2 shift RPM drop, I don't know if they have the same performance potential or no. But Hurst made Dual/Gate ratchet shifters for them, and the one in my green Starfire works pretty well (the blue one is a royal pain in the patoot), so maybe there's more to them than I realise.

[Guest]

Hmmmmmmm, this question got the auto-rebuild juices working. <img src="http://www.aaca.org/ubbthreads/images/graemlins/cool.gif" alt="" /> Since the the main components of an auto trans are the gearing, valve body, overnor, and modulator (vacuum controller of the shift points)in that order, a couple of thoughts come to mind. Firstly, if the gearing drop is so severe between 1st and 2nd, as the esteemed and muchly appreciated Rocketraider pointed out, a different planetary set that connects the two would be possible (with interchanges and with GM internals, there my be many, think 'bean counters'), that would change the ratios. The second is the valve body. Within the byzantine maze lurking underneath your transmission, is a valve body that is really a hydraulic computer. Within said item, are various springs that have a small check ball either underneath or above them that allows either fluid to flow through them, filling a chamber with pressurized fluid that will activate a piston to engage a clutch set, therefore changing gears, or a band to grab a planetary hub on the outside of it to do the same. The tensile strength of these springs determine the shift and release points and either the harshness of the 'handoff' or the smoothness of the engagement. What you gain in stronger and higher rpm shifts, you typically lose in smoothness. It's a balance, because with a smooth shift, each gear is still partially engaged. by changing the valve body springs, as in a B&M shift kit, you will essentially change the nature of the transmission's behavior and shift points at various rpms. The only stickng point is, who would have this data and therefore, parts? Anything is possible, with the right data and a market to make it worthwhile to develop it. Any old racing articles about that trans? Might be worth checking out. I think that somebody out there might have the secrets.Time to play Sherlock and chase names in some old articles methinks. If I knew the model of this transmission, I could find the internals in one of my catalogues. I'd be interested in expanding my non-existent knowledge about Olds transmissions. "Never underestimate a twisted mind with an eye to performance" hahah

[Guest]

Thanks for the reply. It was call a model 10, if I remember right. And I'm looking at a picture of the transmission right now. Can you explain the difference between the Olds Slim Jim Torus, Torque Multiplier, and a Torque Convertor? It looks about the same in the pictures. Was wondering if I could just check the specs, and see if a 2500-2800 rpm stall speed convertor would work in place of the Torus and Torque Multiplier. With the 2.93 1st gear ratio of the trans, it would get off the line quick. Am I dreaming too much?

[Guest]

After reading your post, I did a little homework and came up with the following site: http://www.autotran.us/rhmkits1.html

I looked at the exploded view of the torus, and my feeling is that unless you can find a torque converter that matches all of the dimension, ie., the spline pitch, diameter and depth, outer diameter of the driven torus shell, and the front pump driving dogs, you are pretty much stuck with what you have. It is interesting to note though, that this unit can be taken apart. An adventuresome soul could get a used one of these, and possibly have a knowledgeable welder install some directional fins that would approximate a moderate stall speed. The internal fins would provide a better 'grip' on the fluid, and create a better engagement and a virtual 'lockup' at a certain speed. But, that's a fluid hydraulics question, and a bit out of my league <img src="http://www.aaca.org/ubbthreads/images/graemlins/smirk.gif" alt="" />. i would think that the person that has the kits on he link that i'd posted might be a world of help to you. Good luck!

[rocketraider]

It's official name was Roto-HydraMatic 375 Model 10 in the full size Olds and Pontiac and Model 5 in the Olds F85. Olds used it across the board 1961-64. Pontiac used it only in the Catalina and Grand Prix, and Cadillac would have nothing to do with it.

MasterWrench, these transmissions are a different animal. They have planetary gearsets, valve body and governor, but shifting is controlled by throttle valve position instead of a vacuum modulator, same as a Chevy Powerglide or later 200-4R. The carb-to-trans linkage adjustment is critical to proper operation.

The torque multiplier or Accel-A-Rotor as Olds called it, functions similar to a torque converter and operates only in 1st and Reverse. As the drive torus spins at engine speed, it directs oil to the driven torus blades and spins it. The driven torus directs some oil back to the Accel-A-Rotor, which then directs it back to the drive torus and assists the engine in multiplying engine torque.

The 4-speed HydraMatic was even wilder- it had two separate fluid couplings to accomplish the same thing. But it was a lot stronger and more reliable than the SlimJim.

As far as putting a later type torque converter on one of these, I'm gonna say it won't work without a whole lotta modification. You could probably get a Turbo-HydraMatic case modified to fit the early Olds engine as cheap as doing all that.

[Guest]

Too true! They certainly are a different animal, I found a site with an exploded view of these, and after 3 cups of coffee and a mental image of it's workings, it is a whole different breed. Your expertise at both facts and understatement never cease to impress me <img src="http://www.aaca.org/ubbthreads/images/graemlins/cool.gif" alt="" /> It's always interesting reading your posts, whether germain to my car or not. A person can never know enough.

[rocketraider]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">After reading your post, I did a little homework and came up with the following site: http://www.autotran.us/rhmkits1.html

</div></div>

What a great website! I can get a used 64 Starfire SlimJim easy enough. This website might convince me to try rebuilding one myself! Rebuilt a PowerGlide and a Turbo 350 for auto-tech school years ago, and since then I always found it easier to let a pro do it. But when the pro sez, "I don't know a thing about them" you do what you must. The pro's daddy could rebuild the things in his sleep, but he died too young.

[Guest]

Mr Rocketman. Was just wondering if those Starfires you have, are all stock enginewise? And the Slim Jims still working ok?

[rocketraider]

Both my Starfires are all stock. The green car's Slim Jim works great. The blue one has a couple bad leaks and does a really weird 1-2 shift sometimes (weirder than the normal 1-2 shift <img src="http://www.aaca.org/ubbthreads/images/graemlins/crazy.gif" alt="" />), and a chronic 4GC carb problem aggravates it- sometimes it will stall completely shifting from 1st to 2nd. I should just toss the carb and replace it, as I've been thru it half a dozen times. It'll work well for a while, then the same old float level problems will start cropping up. An old-time carb guy told me last summer that newer rubber tipped needles don't work well in those carbs and you have to set the float 1/8-1/4" higher using them.

It's also one of those carbs that if you set the choke to specs, or even to where it just functions, it never kicks off fast idle. Set it to where fast idle kicks off normally, the choke never closes. This with all the adjustments made and an NOS choke thermostat. When I got the car in 1982, the secondary throttle plate choke lockout had the secondaries physically locked out, so I think the thing was junk from the git-go. The old gentleman I bought it from said the carb had never been touched since he bought the car new.

Right now, even with a new fuel pump and filter, and all new rubber fuel lines from tank to carb, I can't get any fuel to the front of the car so the blue one just sits. I guess I need to take my own advice and drop and clean the tank. That may have been part of the carb problem all along too. But that car is stored in a shed at my parents' place, and in winter I just don't feel like messing with it.

[Guest]

Mr Rocketman. On the Rochester 4GC's, I heard that sometimes the floats get fuel logged, so they fill up with gas and cause problems. On my 1962 Olds 98, I didn't feel like rebuilding the 4 barrel, and the cost of a rebuilt one was higher than I wanted to pay, so for $257.00 I bought a brand new 800CFM Edelbrock carb and put a 2 inch tall TD 4 hole spacer under it. The spacer has 4 holes, and each hole has about a 1/8 wide slot cut at a 45 degree angle that is suppose to give better mixing of the air gas. All I can tell you is the big 98 does not bog at all when you jump on it! And throttle responce is real good. Funny story about the idle screws if your bored and want to hear it.

[rocketraider]

How did you hook up the throttle and TV rod linkage? I bought a new in the box Carter AFB for the blue 64 several years back but found that the linkage worked backwards from the stuff on the car so I never installed it. Does the Edelbrock version of AFB connect different? Guess I could use a Lokar cable or something.

Actually my floats tested good. Good thing because they're no longer brass, they're unobtainium.

[Guest]

Sorry, I'm not sure if the carter linkage is any different than the Edelbrock. What I did was go to the Hires Speed Shop, and got what might have been a Mopar linkage part ( Edelbrock part ) and then go to the junkyards and got all kinds of adjustable linkage rods and parts. I got a piece of flat stock metal from the hardware store ( 1"x4" ) that had some holes in it. I took it to work ( Air Guard Base ) and bent it so it was at the right angle with the carb linkage. I mounted it on one of the intakes bolts that have the big washer on it. So here is what I ended up with. A bent piece of flat stock at a 30-45 degree angle that bolts to the manifold bolt. Another piece of flat stock that bolts to the angle flat stock, so it can pivot back and forth. So the flat stock piece has three holes in it. One hole for where it bolts to the angle flat stock, and two more holes above that. One hole for the carb linkage, one hole for the trans linkage. I mounted one on one side, and the other one on the other side, for better alinement. Try to noticed how the orignal linkage is, so the tension will be the same. I used some all thread so I could have plenty of adjustment area. Since then, I got an Offy 2X4 intake, so I will be at sqaure one again. So would you ever want what I have now, if you decide to try again? Steve Andrews. VA46CLANSMEN@YAHOO.COM Navy Sqaudron Name. A7-E jets.

[Guest]

Just a thought about the Model 10 gearing. If that trans was built for 6 cylinder engines too, I'd be willing to bet, the 1/2 planetary set is different. If you have a huge rpm drop with your 8cyl, Rocket, you can be pretty sure the engineers made the gearing different for a 6. Knowing the cost containment policies of corporations, I'll bet all the external dimension of the hub for band engagement is the same as the one in your Starfire. If you know someone that owns a junkyard near you that's been around a while, the Holland and Holland interchange books might have the differences and the ratios. They have been around a loooong time and have an excellent database. there's your motivation to rebuild you own! Retro-speed freaks unite!

[Guest]

The rpm drop was from the 2.93 1st gear going to the 1.56 2nd gear. Kinda like the 700 overdrive, 3.06 1st and a 1.62 2nd gear. I left the book at work, but the F-85 and Cutlass ( bad speller ) had a smaller trans, and gear ratios wasn't that much different. Good try though. So Master Wrench, you ever play with the old stuff,1964 and older?

[Guest]

Funny you should ask,lol. My last old car which I parted with 2 years ago, was a 1934 Rolls Royce 20/25 Sedanca De Ville with a custom aluminum body my Mulliner, registration number GUB68. It was all black with burgundy hides and was in amazing shape. that model was a 'junior' Roller because it was about a foot shorter and had a smaller engine, only a 6 cylinder OHV with roller tappets!It is an ex-general Montgomery automobile and was used as his personal transport. Montgomery was also the general that McArthur hated, for his lack of resolve in the italian campaign as I recall. but he made his made hi mark at the battle of El-Alemein. (sp?) An extremely interesting car, but not particlularly valuable, I only paid 15k for it and drove it home. I did make a bit selling it though. <img src="http://www.aaca.org/ubbthreads/images/graemlins/smirk.gif" alt="" /> But I'd have rather had a Deusenburg of the same year,lol, too bad it would have been about $100k more, haha. Oh well. I got a big kick out of driving it to my office in uptown Atlanta and doing a few weddings after people chased me down on the street to ask, literally,lol.

[rocketraider]

I've been looking thru the 1961-64 service manuals and the HydraMatic sections are thoroughly screwy. These things are supposedly 3-speed units, but 1961 is the only one that functions as a 3-speed. 62-64 are called 4-speeds in the factory manuals and go into detail about four different stages, with 1st gear ratios from 3.56:1 to 3.32:1 depending on the year. 2nd, 3rd and 4th appear to be fairly constant at 2.93, 1.56 and 1.00. It doesn't say when or where the deep first gear is used or if it starts in 2nd, or skips 2nd (a good reason for the shudder-clunk-lurch shift), or what. I've never felt one shift more than twice, and I've driven Starfires, 88s and 98s from that time period, as well as a couple of SlimJim equipped Pontiacs. They all do the same thing.

It's no wonder nobody wants to work on one of them <img src="http://www.aaca.org/ubbthreads/images/graemlins/mad.gif" alt="" />

[Guest]

If there are 3 gears there or even 4, and they aren't working, I'd hazard a guess that you might have a valve body problem. It might be in fact, 'skipping' a gear. The valve body springs are very susceptible to weakness over time and breakage. After looking at how basic the valve body is on that beast, I'd contact they site I posted for rebuild kits and get a valve body kit. It would probably surprise you with the the sludge and debris that you might find. since you've already done a couple TH trannys, it would be no biggie for you. One fragemnt of a clutch lining keeping a check ball open could leave a piston circuit functionally dead. The rebuilder would surely have a valve body schematic sheet with the kit. <img src="http://www.aaca.org/ubbthreads/images/graemlins/grin.gif" alt="" />

[rocketraider]

Hee-hee.. I just dug out a 1969 printing of the 1961-64 SlimJim parts requisition sheet- the one the dealer mechanics used to order parts for these things.

From 1961-64, there were NINE different valve bodies used in them. Nine different part #s over 4 years, and all but two were revisions trying to get them to shift smoother. 1961 alone had three revisions.

But looking at the exploded drawings in it convinces me I could rebuild one, as long as there's no special HydraMatic-only tools involved. That might be my project in the local community college's DIY auto shop class this summer, if the state government cutbacks don't get it.

[Guest]

Glenn, sounds like you are mentally almost there to do it yourself <img src="http://www.aaca.org/ubbthreads/images/graemlins/grin.gif" alt="" />I rebuilt a ZF-HP22-4 auto completely in my home garage about 5 months ago. A very complex beast with 4 forward clutches, no bands, 2 compound planetary sets and a 3 level valve body. I replaced every clutch, steel, seal and valve body spring. It took just the weekend, with no special tools, but I have a pretty comprehensive selection, and I had the beer AFTER I did it,lol. The rebuild manual was relatively vague in some key areas, so I took notes. A neat trick is to get a piece of paper while you have the valve body upright, and place it over it, then rubbing the surface of the paper for ecah level of the valve body. That lets the fluid make you an image of where everything goes. Also, measure the check balls with a mic or a caliper and then have a little plastic lure box handy for each one and some small stickers or masking tape for location numbering labels. Just number them and the valve body paper alike and you can't lose. Doing this german ZF was a challenge, and even the dealers don't do them anymore, they said I was nuts. The highest compliment to the mechanically inclined and intellectually adventuresome, haha. Most importantly it works! Upon disassembly , the problems were obvious, and it was a valve body problem that burned the front clutches. There was a design flaw, so armed with an 'update kit', installed that also, and elimnated future repairs. The interior parts were absolutely beautiful pieces of engineering and machining. Examining the parts, understanding the function clearly and visually, was a richly rewarding experience, and saving 2100 bucks, (total parts cost $192) didn't hurt either <img src="http://www.aaca.org/ubbthreads/images/graemlins/smile.gif" alt="" /> Just make sure you have some un-interruped time, no dust, great lighting, compressed air source, brake cleaner or a parts tank, and a spotless workbench. Beethoven or Debussy for music and AC/DC when you are finished. <img src="http://www.aaca.org/ubbthreads/images/graemlins/smirk.gif" alt="" />I re-assembled everthing on a roll of white enameled paper, with a small plastic butter tub fill of atf for soaking and dipping assembled parts. also, get some red transmission asembly lubricant for pistons and seals, it's basically just tinted vaseline, but is tinted to spot early pressure leaks. You can do it,pardner, after all, there is little to lose, and much to gain. <img src="http://www.aaca.org/ubbthreads/images/graemlins/smirk.gif" alt="" />

[bigfoots98]

Sounds like you're already halfway there. Dave Edwards at Autotrans.us has the kit you need. After going around in very costly circles trying to have my slim jim properly rebuilt, I finally picked up two boxes full of loose parts, the case, and rear bearing retainer from the shop that couldn't put it back together. Then, using my ability to follow directions(somewhat), I proceeded to inspect and reassemble the beast using the Oldsmobile Shop Manual. I replaced the broken sealing ring on the accel-a-rotor(which was the wrong size, hense the repeated failures over two years), and replaced all o-rings and seals. Well what do you know?? The yaht sails again!! I've put almost 1000 miles on it and so far so good. The only issue is that I'm STILL trying to get the throttle valve linkage properly adjusted without the proper, now obsolete tool. I'd say go for it!! If you find a shop that's not afraid of it they're gonna certainly charge you $2000 or more to touch it. Good luck!!