[Night Wolf]

Hello everyone, I'm new here, but not to automotive message boards, I figured I would try a site that alot of people have experience working with these transmissions as nobody else knows what it is.

Anyway, I've got a 1989 Cadillac Fleetwood Brougham. It has an Olds 307/200R4 combo. I am wondering if anyone has ever heard or seen this problem before.

The speedometer will not work when the car is in drive, in 3, 2 or 1, it will not work either. But coasting at any speed, if you bump it into neutral, after a few seconds of staying at 0, the speedoemter needle will jump up and read your speed perfectly, put it back into drive, or any other gear selection, and the speedo needle drops like a rock back to 0.

On the highway if driving around 75mph+ after a while the speedometer will actually start to pick up a bit, but only go up to 25-30mph, and shake while doing it. When shifted into neutral the speedometer is really steady at the speed.

I got the car a few months ago, its a slow project for me, but it was my mothers car for the last 9 years.... It has been like this for ~5 years now, so the mileage on the car is unknown, but without a speedometer, the speed sensor connected to the speedo dosn't register speed to tell the torque converter to lock up, so the TC is always unlocked, even on extended highway trips, and finally, the cruise control, which I just fixed, relies on the speed given from the speed sensor, which dosn't work (or when the speedo goes to ~30mph and flutters bad, it works very poorly)

I'm really hoping someone here has heard of something like this. I really don't know what to do, I've called some local transmission shops and nobody has ever heard of it either.

If nobody knows what it is, when what, inside the transmission changes when shifted from neutral to drive that would effect the speedometer gear? Heck I can even get a video of me driving the car and putting it into neutral etc....

The car needs alot of work, its getting there but this is one thing that really has me stumped. Thanks in advance for all your help!

[jakeshoe]

I'm going to make a WAG here.
'89 Caddy has an electric speedo and one of the oddball gear driven speedo bullets that converts mechanical to electrical pulse. Right?

If so,
I think you may have a ground issue either in the dash or the trans that is causing your problem.

Check the wiring from the speedo pickup to the dash area and see if the shifter linkage is rubbing it.

be sure the ground strap is attached from the trans to the body.

[Night Wolf]

'89 Cadillac Fleetwood Brougham is old school... carburator and cable driven speedo...

[jakeshoe]

Originally Posted by Night Wolf

'89 Cadillac Fleetwood Brougham is old school... carburator and cable driven speedo...

I don't think it came that way...

[Night Wolf]

Alright, a bit more history, I was gonna try to keep it simple, because I am known for long, detailed, in-depth posts, and being new on the site, alot of times some people don't take kindly to them... but here it goes.

Car was my mothers since 1998, she bought it in Ft. Lauderdale with 76k miles on it, it was driven up to NY, undercoated, and was her only car for the last 9 years.

About 5 years ago or so, when the car had ~135k actual miles, the origanal tranny went out... not an uncommon thing at those miles for the 200R4 in the Caddy's.

The car was brought to a very reputable shop in upstate, NY for a tranny rebuild. Well, what they do is take the cores, rebuild them when they are slow, and then when busy, they have a rebuilt trans sitting on the shelf ready to go in the car.

So the tranny that is in the car now is not the actual origanal tranny, but same version etc...

That is when problems with the speedometer started. Everything was fine, until one night my mom got pulled over for going 12mph over the speed limit, twice in a row, on the same road.

Thats when we decided to clock the speedo... sure enough, the speedometer was reading 12mph UNDER the actual speed, casuing you to go 12mph over to think you are going the correct speed.

Because of the rebuilt tranny, we thought the trans was from a different type of vehicle that had a different speedo gear, so we brought it back (few months after we first noticed the issue) asking them to drive it, and possibly change the speedo gear. They said they never touch that part of the trans doing the rebuild, and the gear should be correct... none the less, they drive the car, clock it with another car, and it was 12mph off.

So they bring it back, change the speedo gear and take it back out... now the speedo is dead, so they bring it back again and manage to get it to work.

Well, that was fine, then maybe in the course of a couple months, the speedometer would slowly and slowly read under the speed limit until it would rest at 0 the entire time driving.

We never bothered to bring the car back, as it was already probably a year after the inital tranny rebuild, and my mom, who is on disability from a major car accident only would drive local for the most part to doctor apointments and various things in town she would volenteer to do, so she got used to simply not having a speedometer.

As it is now, when I shift into neutral, there is a few second delay, then the speedo springs up and levels out at the actual vehicle speed, as I've confirmed with my GPS, above 30mph the speedo needle is super steady, then under 30 there is slight flutter which is no doubt from the origanal speedo cable. I have a brand new speedo cable I was gonna put in, but I don't see how that would do anything seeing as how it works fine in neutral.

Her and my step father moved down to Florida last year when the car made the trip from NY to FL, pending the sale of our house in NY, they were going to buy themself a new old car, when they did, they said they would give the Brougham to me. The thing needs alot of work and isn't worth anything. I learned to drive in this car and took my road test in it, 4 years ago.

So I've been slowly fixing it up, I have 3 vehicles, and the Caddy is last on my list as it is my project. So far I've fixed quite a bunch of stuff, but the speedometer issue has really gotten to me, because first, the real mileage of the car, which is defintily over 200,000 miles right now, is unknow, as the odometer currently reads 43,xxx, it rolled once, but in the last 5 years only logged on 3-5,000 miles, because at highway speeds, it will in fact come up to 25-30mph. Example, I live in Georgia, I took the car to my parents place and back one weekend, a trip of about ~450miles Most of the time the speedo read 30mph, and thus on the entire trip, it actually logged on 124 miles.

Besides not logging in the miles, there is no torque converter lockup.... making fuel mileage worse, revving the engine higher and heating up the tranny more. I could bypass it and wire up a switch to lock up the torque converter, but I don't want to stick a bandaid on it, I want to fix the speedo. Finally, the cruise control relies on the speed sensor to maintain speed, not stright manifold vaccum, so with no speedo, or an incorrectly functioning one, there is no cruise control, and I am an avid user of cruise control on the highway.

Car is factory though.... it comes as a shock to many that a late 80's Cadillac is carburated, especially since the 1981 RWD Cadillac which used the big block 368 with V8-6-4 was fuel injection, and 1982-1985 RWD Cadillacs used the HT4100, which too was fuel injection, then '86-'90 switched over to the 307 with 4bbl carb. The 1990 307 Brougham was the last GM car to have a carburated V8. 1991/1992 base engine was the fuel injected 305, with the 350 optional, then in 1993 the RWD Cadillac was restyled to be the '93-'96 Fleetwood, with the standard 350 in '93 and the LT1 from '94-'96.

Here is a picture of the car... along with the 307. I put the air cleaner on it because I had it left over from my '79 Sedan DeVille d'Elegance that was wrecked last year.... same chassis as the '89 Fleetwood Brougham but with a Caddy 425 4bbl/TH400.

[Night Wolf]

Originally Posted by jakeshoe

I don't think it came that way...

cable driven speedomater on these cars were in fact standard even with the '82-'85 fuel injected HT4100. The RWD Brougham didn't get an electronic speedometer until 1990 when the instrument panel went digital.

[daoldbuick]

The way to narrow it down to where the problem is, if it's a cable drive, remove the cable from the speedo and go for a drive. If the cable turns continuously and in relation to the speed your driving the problem must be in the speedo if it doesn't its in the tranny

[Night Wolf]

I was thinking the same exact thing, just pull the cable from the speedo and take it out.... I'll do that and see what happens.

[lust4speed]

The 200R4 drives the speedometer cable off the govenor gear. The first part of this gear has to be okay or your trans wouldn't shift, but I suspect that the problem is the mesh of the speedometer portion of the governor gear to the gear on the end of the cable. I would also say that being able to get a reading in neutral would back this up. There is probably enough slop in the gears that they come a little closer together while coasting in neutral. Pull the cable and gear out of the trans and see if it doesn't look like an apple core instead of a perfect cylinder. I suspect that the trans shop put in gears that were already trashed when you had them correct the reading.

[Night Wolf]

Alrght, so I'll pull the cable/gear from the trans and see if its chewed up or not?

That would cause the problem, in which cause it is something that can be fixed without tearing apart the trans?

[joe_padavano]

Originally Posted by lust4speed

The 200R4 drives the speedometer cable off the govenor gear. The first part of this gear has to be okay or your trans wouldn't shift, but I suspect that the problem is the mesh of the speedometer portion of the governor gear to the gear on the end of the cable. I would also say that being able to get a reading in neutral would back this up. There is probably enough slop in the gears that they come a little closer together while coasting in neutral. Pull the cable and gear out of the trans and see if it doesn't look like an apple core instead of a perfect cylinder. I suspect that the trans shop put in gears that were already trashed when you had them correct the reading.

You are almost certainly correct. I've had the same problem with one 200-4R and one Muncie. In both cases the cable was worn, resulting in excessive load on the plastic speedo gears in the trans. This causes the gears to wear out. Replacing the gears and the cable solves the problem. Note that the worn gears will work sometimes since trans oil gets on them and creates a hydraulic coupling, similar to the torque converter.

Replacing the gears on the 200-4R is easy. The speedo driven gear comes out the side. Unbolt the adapter where the speedo cable enters the trans and pull it out. The gear slides in the end. Replace the seals while you're at it. The driven gear is on the governor as noted above. Drop the pan and there will be an oblong cover at the back of the case under the pan. Remove this cover and the governor pulls out. The gear is held on to the governor with a snap ring. Plan on replacing the filter while you have the pan off.

And to those who suggested otherwise, ALL cars with 200-4R transmissions used a cable-drive speedo. Where a VSS was required for the ECU, it was mounted on the back of the speedo head.

[Night Wolf]

Originally Posted by joe_padavano

You are almost certainly correct. I've had the same problem with one 200-4R and one Muncie. In both cases the cable was worn, resulting in excessive load on the plastic speedo gears in the trans. This causes the gears to wear out. Replacing the gears and the cable solves the problem. Note that the worn gears will work sometimes since trans oil gets on them and creates a hydraulic coupling, similar to the torque converter.

Replacing the gears on the 200-4R is easy. The speedo driven gear comes out the side. Unbolt the adapter where the speedo cable enters the trans and pull it out. The gear slides in the end. Replace the seals while you're at it. The driven gear is on the governor as noted above. Drop the pan and there will be an oblong cover at the back of the case under the pan. Remove this cover and the governor pulls out. The gear is held on to the governor with a snap ring. Plan on replacing the filter while you have the pan off.

And to those who suggested otherwise, ALL cars with 200-4R transmissions used a cable-drive speedo. Where a VSS was required for the ECU, it was mounted on the back of the speedo head.

Wow, awesome!

So is the problem the speedo driven gear on the side of the trans, or the driven gear on the governor, or a combo of both?

Dropping the pan isn't too bad, becuase I was going to be doing that some time in the near future just to change the tranny fluid and filter.

I've got an entire '87 Fleetwood Brougham as a parts car (also my paretns, but in worse shape) so I may as well just pull the speedo gear... as well as the governor gear? As for cable, I do have a brand new cable, so I will probably just replace the whole cable if the speedo has any flutter to it once fixed.

If it is in fact the governor gear within the pan as well, then I guess I'll have to pull the pan on the '87, just more work, but if thats what it takes to get the speedo working, then I am all for it

Thanks again!

[joe_padavano]

Originally Posted by Night Wolf

I've got an entire '87 Fleetwood Brougham as a parts car (also my paretns, but in worse shape) so I may as well just pull the speedo gear... as well as the governor gear? As for cable, I do have a brand new cable, so I will probably just replace the whole cable if the speedo has any flutter to it once fixed.

Just remember that the gears are different depending on the OEM rear axle ratio and tire diameter.

[Night Wolf]

'87 and '89 Brougham are both exactly the same rear axle
\
I hven't had a chance to work on the car yet, I work nights, 10 hours.... but I will defintily be checking this out and getting back to everyone