So I was driving home from work and heard a light rattling sound. I put the trans into neutral to see if the sound remained or went away, and it went away. Hmmm, I thought as I put it back into Drive. 2-3 seconds later the car slowed slightly and made a sound like a bunch of rocks rolling around in a metal bucket. I threw it back into Neutral and the sound went away. OK, now I'm scared. Put it back into Drive, and 2-3 seconds later the same thing, car slowed and gravel in a bucket sound.

Crap.

Luckily I was only about 1/2 mile from home (just got off I-10 doing 65-75 MPH), so I was able to make it to the house by momentarily putting it in Drive then coasting, repeating this process until I made it to my driveway. It pulled just fine in 1st going over the curb and up the driveway. Later I did some troubleshooting and it goes into gear fine, drives normally until it shifts to 3rd gear, then the gravel noise starts.

So now I have a choice of rebuilding the TH350 or replacing it with a TH200-4R.
I would like to get information from those who have done the TH200-4R swap as to what all is involved. I'm looking for details, like which transmission suppliers make one that can live behind a BBO (future plans are either a 425 or 455), who makes good converters, do you prefer lock up or non lockup converter (and why), and things like what's the best TV cable, how to attach the cable to the '71 QJet, do the e-brake cables need to be modified, are the trans cooler fittings the same thread as the TH350, etc., etc.

If anyone knows of a writeup that would be great. I am still undecided if I go the easy route of replacing the TH350 or go with the TH200-4R.

 

Sorry to hear of the unfortunate demise of your T350. I'm curious also as I don't know anything of the OD transmissions.

 

The first thing you need to know before considering a 200-4r swap is the ratio of your rear end. If you've got small gears in the back and do a lot of highway driving, the 4 speed swap makes a lot of sense.

 

Rearend is currently a '68 O-Type with 3.23 gears, tires are now 245-60-15s (just moved up from 245-60-14s). I have a set of 3.42s for the original 8.5" 10 bolt rear that I was planning to install before the transmission moved up on the priority list. I also have a set of Richmond 3.90s for the O-Type that I had considered installing if I ever got an OD transmission. I am not opposed to turning 3000+ RPM on the highway (been doing it for decades now) but I think a 4 speed swap would make sense for the long term.

 

I know almost zero about this but will eventually do the same thing so I'm subscribing. I recently read that the 4r needs beefing up before it can go behind a small block, let alone a BB. There was a kit mentioned too. I'll see if I can find the post.

 

This is a point of argument without any point to it. The 200-4r came in several flavour, but few of them were backing any serious power. The few that were, were behind the GN's turbos (which at the time were the most HP any GM was putting down, including the Vette, if I recall correctly). While some will argue that the GN and Monty sourced 200-4rs are strong enough to live behind a mild 350 ... why would anyone want to? While it's out on the table being rebuilt, you spend a couple of hundred extra to update the known weaker parts taking all the guessing out of the equation and making it strong enough to make putting a 350 back in .... pointless. Seems like a no-brainer to me. One of those 'pay me now, or pay me later' situations.

 

Well obviously I would not be installing a stock junkyard TH200-4R that was behind a 307.

Some of the choices from one of the major suppliers:

Stage 1
500 hp / 400 Ft-Lbs torque
$1595

Stage2
750 hp / 600 Ft-Lbs torque
$2095

Stage 3
1000 hp / 850 Ft-Lbs torque
$3095
I don't need this level

400 hp and 500 Ft-Lbs would easily work with my current engine but may limit me in the future if I install a BBO.

Getting the transmission is the easy part. What I need to know about is what all is involved with installing it and getting it to work properly after transplanting it into a vehicle that wasn't designed for it.

 

Well, you could start with the SEARCH function...

https://classicoldsmobile.com/forums...-look-out.html

https://classicoldsmobile.com/forums...anny-swap.html

https://classicoldsmobile.com/forums...00r4-swap.html

https://classicoldsmobile.com/forums...vs-700-r4.html

https://classicoldsmobile.com/forums...anny-swap.html

https://classicoldsmobile.com/forums...00r4-swap.html

https://classicoldsmobile.com/forums...a-cruiser.html

https://classicoldsmobile.com/forums...350-200r4.html

 

Sorry about your 350 tranny. I went through the same thing back in July. Big Bang and then I lost 3 rd and Reverse. I did a lot of research on this site and elsewhere. I ended up buying a Stage 1 from Extreame Automatics. Lonnie guarantees this for up to 500hp. He has a lot of good info on the 200r 4 swap at
http://www.extremeautomatics.com/th2004R.php. Go to tech and look for 200r4 install. His transmissions are Based on the Buick Grand National. I followed Lonnie's directions for installation and adjusting the TV Cable. It shifted correctly the first test drive right out of the box. The 200r4 is a direct bolt in swap. You move the crossmember back to the Turbo 400 bolt locations. No cutting or welding necessary. Do your research before attempting this as I read a lot of frustrated posts from people who attempted this and had problems with the TV adjustment. You will need a TV Cable and bracket to fit the carb you are using. I went back to a Q'Jet already equipped with a TV Brakcet. I followed the info on the link above and it shifted dead on first time. You need to check the travel of the TV plunger with the pan off. Once it is adjusted you check pressures to verify all is correct. The whole install went very smooth and it drives like a whole different car. Low gear is a little lower than a Turbo 350. Nice chirp on the 1-2 shift. Shifts firm but not rough. I am running 3:73 gears and cruising about 2200@ 65 mph on the highway. One of the best upgrades I have done.

 

Ken, a 350 can be rebuilt for under a grand. If you're happy with the car the way it is, perhaps pulling the trans, going through it, maybe some small upgrades, and there you go, makes sense.

Also recommend you do some inspection prior to writing off the 350. Perhaps pull the pan and see how fragged it is. Could be you'd be back in power with as little as 500 spent at an old time reputable trans shop.

 

I didn't realize that one would have to switch the tv cable from the accelerator pedal to the carb to make this swap.

 

Yeah, the extreme auto 500 hp claim is nice, but it also has a 400 ft-lb torque rating. A moderate 455 puts out around 400 hp and 500 ft-lbs torque, which may be too much for it. Prolly need to talk to them and see what they have to say.


Thanks for the links, Joe.

Things needed for the swap:

A suitable throttle bracket with a TV cable setup.
Move crossmember back to TH400 location.
Change e-brake cables to TH400 style.
Get metric hardware for trans mount, shifter linkage, etc.

What about the dipstick and tube? Same as the TH350 or different?
And I need to decide if I want lockup or non-lockup converter.

 

This trans was rebuilt about 12 years ago with all HD and hi-po parts (cost me ~$800 then). I am just not really sure I want to do it all over again. That is still an option, though.

 

What about the dipstick and tube? Same as the TH350 or different?
And I need to decide if I want lockup or non-lockup converter.[/QUOTE]

You will need the tube and dipstick from the 200r4.
I used the non lockup. Not that big a deal on fuel mileage for my use and I didn't have to fool with the electrics and switches and such. You are correct on the torque rating. I am running a mild 350 so not such an issue. If you call Lonnie he is a great source of info and could steer you in the right direction.

 

Two different cables.
The TH350 has a kickdown cable - once it moves past a certain point, it activates the kickdown mechanism.
The 200R4 has a TV cable - it provides a constantly varying input of throttle position.

- Eric

 

Ahh, got it. So no kickdown for the r4?

 

The TV cable tells it when to kick down, but it also tells it other stuff.

If you look at it logically, the TH350 kickdown cable is a device that provides a binary signal consisting of a single bit, while the TV cable provides an infinitely variable analog signal.

- Eric

 

Forgot one thing: 4 speed conversion kit for the Dual Gate.

I read Joe's post about not liking the way the gears are set up with these and I kinda agree. 25+ years of driving it as a 3 speed and instinctually "knowing" how to shift may run afoul of the new configuration. Not so much as a functional issue but it might detract from the joy of driving the car as I have known it for the past couple of decades. What if I dislike it as much as Joe did and I no longer enjoy driving the car as much because of it?

Decisions, decisions.

 

It really sucks when something expectantly goes wrong when your making plans to do other work to the car. I had my TH350 rebuild last summer. I cost me $950. up here and I supplied the TCI converter. I recall the shop mentioning to me that it's capable of handling up to 500hp. At that time I was considering a 455 build.
Decisions are always tuff when you have so many options to choose from.
I hope you get it up and running smoothly again soon Ken .
Cheers in trying to making a good decision !!
Eric

 

Just went through this and ended up having the current TH350 rebuilt. Really liked the idea of having OD with my 3.42 rear end, but finally decided I could buy a lot of extra gas for the cost difference when you add up everything in addition to the transmission itself. It's a weekend driver so not a lot of highway miles for me.

 

Are we talking about shift points? 20 years is a long time but we're adaptable creatures. You'll just have to drive it A LOT in order to get used to it. But I feel ya, it will be different.

 

The TH350 cable that goes to the accelerator is NOT a TV cable, it's a kickdown cable. The functions are very different. The TV cable combines the functions of kickdown and the vacuum modulator and is essentially a mechanical throttle position sensor. The TV cable includes the special self-adjusting ratchet feature to help get it set properly. There is no such cable that will work with the A-body accelerator pedal cable design.

 

No, the physical manipulation of the gear shift mechanism. I drive with the Dual Gate on the right "his" or "race gate" side 100% of the time, so having the OD position on the "other" side will be weird, especially when manually downshifting (which I do a LOT).

I'm sure I could get used to it, but would I like it? A lot of the fun of driving this car is that I have been driving it since I learned to drive back in high school, so I wonder about changing something that is ingrained, comfortable, and second nature.

 

update:

After much web searching I found that the TH350 dipstick and tube will work in the TH200-4R. It will read 1 quart overfull, but apparently it is standard practice to run an extra quart in the TH200-4R to ensure the top draw filter assembly does not become uncovered and pull in air under hard acceleration, which would result in reduced fluid pressure and premature wear.

Next item is a TV cable bracket for the original QuadraJet 7041250 carburetor. It appears I need an attachment arm for the cable end on the existing carb linkage and also a cable holder bracket for the rear of the carb.

Does anyone know if these are specific to Olds carbs or would the parts from any GM QJet (aka Chevy) work?

 

Put a pic up of the linkage. Not sure how different they are from later carbs. The factory 307 throttle/TV cable bracket works great with the late 70's carbs. I would get a universal adjustable bracket and cable. You need slight tension at idle and full pull by full throttle. If you run the 3.90 gears, I would go lock up. If you stay with your 3.23 gears, no lock up. I run 1850 rpm at 60 mph, lock up engaged with 245/60R14 tires, speedo bang on according to GPS.

 

Kenneth, If you're going to be at the annual Olds show March 28 at the Pavillions, I can answer pretty well all your questions since I did the TH350 to 200-4R swap in my 70 Cutlass and now have all the bugs worked out.
Harold

 

I just did a quick search and see what you are saying about others using the TH 350 Tube. Curious on how they make this work as I remember the sealing ring on the 200r4 being different from the O ring on the TH350. Also I do not think the 200r 4 has a provision to bolt the tube to the trans case like the Th350 tube has. I used the TCI Tube from Summitt. It is not a perfect deal either. It comes with an auxiliary bracket that I had to use, and the Tube needs to be shortened to get the correct reading. It sits much taller in the engine compartment than the original tube so it does not look stock. I also installed a deep pan and bottom feed filter on mine just to be safe. I didn't want to take a chance on fluid foaming by running a quart to much. This is probably not an issue, but, I do a lot of road miles and wanted to take the extra precaution.

 

x2 on above. I am running the original 3 speed dual gate with the 200r4 and about to buy a 4 speed conversion kit. I respect Joe's opinion, so I am now thinking twice about this. Any comments from others who have already installed this? Pros or cons.....

 

If you are running a Qjet, the easiest way to hook up the TV cable is to get the primary throttle shaft from a CCC Qjet and swap it into your earlier Qjet. Use the cable and bracket from any CCC 307 and this is a bolt-in.

Just out of curiosity, why aren't you using the original 200-4R dipstick and tube?

 

Kenneth, check your PM. Also I did a write-up on a 200-4R swap in the Jan 2014 issue of the Olds Club of Az newsletter, page 19 It's available online.

 

I was planning to go until the trans failed. I was hoping to have it running again by then but with work and an upcoming vacation I don't know if I will make it.

Thanks, I'll look it up. I was going to ask you for all the little details.

I currently do not have a transmission, so I would be purchasing it from one of the reputable aftermarket suppliers. I did not see on any of their web sites that the trans comes with a dipstick tube, so I am researching to find all of the little items I need for the swap.

 

Ken,
Did you end up putting it in our sticking with the th350

 

I decided to have the TH350 rebuilt as it was simpler and faster than doing the OD swap. I didn't feel like bench pressing transmissions so I brought it to the shop that did the rebuild 15 years ago

Sorry for not updating this thread.

 

Go to monster transmissions they'll hook u up

 

What was the box-o-rocks noise?

 

The shop owner said a rear sprag came apart? He said this can happen from a 1-3 shift under load, which kinda happened as right before the noise started I had turned a corner and the road was all wet from an irrigation system leak. I floored it and the trans downshifted to 1st, the rear tires started spinning, it shifted to 2nd then immediately to 3rd and I let off.

 

This is good info to know so others can know what to avoid if all possible; thanks for sharing and glad it is fixed now. Does anyone know if this is a common failure mode for these trannies?