My 200-4R tranny started to make some very bad noises a month ago in 1st & 2nd gear, Drive & overdrive were ok. Removed the tranny and it is at the tranny shop now.
A year ago I changed out my Th350 in in 75 Cutlass when I had the motor rebuilt. I put in a beefed up rebuilt 200-4R with a dual hump crossmember and slid it back to the Th400 location.
New tranny mount and motor mounts installed at the same time. New u-joints front & back.The th350 drive shaft slide in with no issue and everything bolted up as it should.

Move ahead to this year. My tranny guy called and said the it appears the driveshaft had moved forward into the tranny to the point it did something to first & second gear.. I don't have all the details. He asked me if it was real tight going in. I said no, I have had the drive shaft out 3 times with the 200-4R in place with no issues.

Here is what I do know.
1. During breakin with the new cam in the shop, my car got quite hot and the underbody tar dripped along the top of the driveshaft. I didn't know this at the time... Took the car out on the highway after the breakin and had quite severe vibration at 70- mph.. Didn't know what it was at the time.Removed the driveshaft, replaced the u-joints again and cleaned the tar off... All good now for vibration. *** I doubt this was cause ****

2. Did a few break stands and did hard launches during some test and tuning setting up my timing and carb jets. Is it possible I have week upper and lower control arms/worn bushings allowing my 3:42 posi diff. to nose up quite a bit moving the driveshaft inward towards the tranny??? I'm thinking it would have to move quite a bit...

No other explanation I can think of.

 

How much clearance is there before the driveshaft bottoms out in the back of the trans? What exactly is broken or damaged in the 200 trans?

 

There should be 3/4" clearance between the tail shaft housing seal face and the bottom shoulder of the slip yoke. However, this makes no difference if the end of the slip yoke bottoms in the trans before the 3/4" is consumed. They do make yokes with different length splines. Maybe you got a long spline?

I recommend removing the pinion flange straps and then measuring the distance the slip yoke travels into the trans. You need at least 3/4" to compensate for rear suspension articulation. This measurement must be made with the weight of the car on the wheels for the axle to be at normal articulation.

If the above checks out, I'd be looking for worn control arm bushings, etc.

 

I need to find out more on the failure... he just told me over the phone he thinks the driveshaft pushed into the tranny slightly causing the first & 2nd gear failure. I can't remember the terminology he used... He did ask if my driveshaft was too long. I said No, I didn't think so.

 

bry593, I think I have the clearance, but not 100% sure. When I removed the driveshaft from the diff. taking the straps off, I pushed it forward into the tranny and then dropped it down... He said it didn't push the damaged parts very far in. Just slightly.... Currently the tranny is out of the car at the repair shop... In the mean time I need to do something. I will check the clearance when it goes in for at least 3/4" at the back when the yoke is pushed into the tranny all the way.
Would worn upper or lower control arms cause and movement.
Which ones to replace first. Not cheap. May replace the whole arm assembly. I know bushings are cheaper.

Jeff

 

What is the length of your yoke and how deep are the splines, I have my 200-4r apart and took these pictures and what the transmission shop is saying doesn't make sense to me. The yoke I have is a turbo 350 6 1/4 long fully splined, and as you can see in the first picture there is about 1 inch before you hit the governor gear which is the first thing you will hit in the transmission. the second picture is with the yoke pushed all the way into the trans case and you still have abut 3/4 of an inch before it hits the governor gear. The only thing I can think of is that you yoke is not fully splined and it bottomed out on the output shaft , pushing it forward and did the damage. I would think that would take out more than just first and second.

 

Correct, the spline may not be broached deep enough inside the slip yoke.

Incorrect, it will not hit the governor. The splines will slide to the hob rollout (end of spline) of the output shaft and stop long before contacting the plastic governor gear.

 

I will check the yoke length & splines this weekend on my spare Th 350 . I will get a measurement of the total length of the driveshaft from the tip of the yoke (tranny side) to far end of the driveshaft (pinion end) with the yoke in place.

Thanks

Jeff

 

What parts broke ? Not my pic, its from grumpysperformance.
I have two 200r4s on the bench now. Most likely one of the stupid plastic washers went. I rollerize ours.

 

Old403, great picture. I will have to find out when I get more info. I have not been in to see the guy yet... Only a quick conversation on the phone. I will post when I find out the exact issue.

.......... I did some measuring today. Total length of my driveshaft from tip of yoke to end of the (driveshaft) pinon end where the u-joint is held is 59-7/8" long.
The inside of the yoke when measured from the opening to where it bottoms out is 4-5/8" and splines go all the way to the end.

 

I picked up my tranny tonight from my tranny guy... I think I have the terminology right, some how my driveshaft yoke came forward and slightly bumped the sun gear rear carrier assembly which damaged the sprague clutch. Some pcs from the sprague got into the planetary gears and wrecked them as well. That's why it only made a very bad noise in first & second only and in neutral it wouldn't go backwards. 3rd and OD there was no issue once I shifted out of 1st & second gear... So I replaced both rear upper and lower control arms with new arms and new bushings with the rear end in place.. Not something I want to do again. I will also measure the driveshaft yoke play once installed.

 

That is very deep in the trans and a full teardown.

 

* You must have the correct control arms, speaking of the rear or it will pose some problems. The lower control arms not so much, but the upper are somewhat tricky whereby you must install the right arms: Three fitments available for a 1986 Oldsmobile Cutlass Supreme: Upper Control Arm:
1.) 10000076 - 0 DEG; CODE XR, XN, XP & XX
2.) 10001060 - PLUS 1 1/ 2 DEG
3.) 10001059 - MINUS 1 1/ 2 DEG
Not sure of your year or model. The upper control arms are critical and could affect many suspension problems.