Just a warning, I'm asking a lot of questions in this thread so sorry for such a long post! Any help would be greatly appreciated.

Okay, so I recently purchased a 1991 305 TBI T5 Camaro that was HEAVILY neglected.

I have a thread up about some of the cosmetic work I've done in the body section, but I would like a little help in this arena so I'm making a thread here.

Basically, I believe my car was sitting for a few years before the previous owner purchased it (and he had it for only a few months.)

I have got it driving very well actually, and it seems pretty reliable now. However, the odometer/trip meter and speedometer have issues that are very annoying to me.

1) ------------------INCORRECT SPEEDOMETER READING------------------------

First off, the speedometer did not read correctly. It was reading a percentage slower, and at 50mph on the speedo, I was actually going 65 (with GPS on my phone.)

I believe this means either the transmission was swapped at some time, or the rear axle gear ratio was changed. With an electronic speedometer, I still have to change the Driver/driven gears correct?

Is this an all day job, or can I get it done in a few hours? Also, where can I get the gears once I figure out what ones I need?

2)-------------------STUCK TRIP/ODOMETER------------------------

My Odometer and trip meter are stuck and don't move. At first, I took the cluster out and checked the gears in the speedometer assembly. All the gears are in tact. I used compressed air to blow out dirt and sprayed some WD40 (I didn't have any other lubricant on hand) and put it back together.

This seemed to get it working VERY intermittently. The trip and odometer numbers would move, but eventually got stuck (mostly when the trip meter was at 0009) and I would have to hit the trip reset before the numbers would move again.

I dug some more into the cluster, and it seems as if the TRIP mileage assembly sometimes hits some "hard" spots where it is more difficult to turn. It seems like an internal thing inside the trip thing and I didn't know how to take it apart. Is there a good way to clean/fix a rough moving trip mileage assembly, or should I be looking for a new one?

3)----------------POSSIBLE DAMAGED ODOMETER MOTOR-----------------------------

Despite having the trip and odometer numbers partially functioning, they did NOT seem to be moving appropriately to the speed I was going (based on what the SPEEDOMETER read.) They seemed to be moving much slower than they should for what the speedometer was reading, and since the speedometer reads slow in the first place, they were not moving much at all.

I decided to try my luck and take a look at the motor that turns the gears. I took the top of the motor off, and it look fine on the inside (didn't really know much what to look for.) However, after I did that (I also re lubed the gears and the trip/odometer assembly, and they turned by hand very smoothly for the most part), they stopped turning all together now that it is installed back in the car. I don't know if I messed up the motor taking it apart or if I didn't put the face plate of the motor back on correctly which would cause the gear on the motor to not spin with the inside. Does it sound like I messed up the motor (and maybe can just put the face plate back together), and are there any places I can get a replacement if it is damaged or worn?

4)----------------INCORRECT SPEEDOMETER NEEDLE POSITION------------------------------

When I did mess with the motor, I had to take the speedometer needle off to access it in the first place. I read somewhere it might cause issues if you do, but because of the odometer issues and the speedo reading incorrectly in the first place, I didn't have much worry.

Once I put my cluster back in though, the speedo now STARTS at about 37MPH and moves from there. I'm assuming not, but is there an easy way to adjust the needle so that it starts at 0mph?



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One more question, after all this mess that was there and what I caused, I am looking at speedometer assemblies on eBay in case that's what I have to do.

Will a V6 instrument cluster speedometer assembly work fine in my cluster as long as it is electronic?

I assume if I get a mechanical speedo, I will need to swap some parts on the transmission and I don't have much money to spend buying many more parts.



Any other suggestions or fixes would be greatly appreciated. I'm trying to get this taken care of so I can better track my MPG and also mileage on the car in general. Plus, having a working speedometer is much more convenient than relying on my phones GPS.

By the way, here is a link to my thread in the body section for the progress on restoring my car: https://www.thirdgen.org/forums/body...enix-down.html

 

1) swapping a DRIVEN gear on the sending unit will take very little time. remove 1 bolt, pry the VSS out, swap gear, and re-install. If the DRIVE gear on the tail shaft needs to be changed it will take longer. Use a jack to support the tranny pan/engine, remove the Torque Arm @ the tranny end, remove the cross-member, remove the tail-shaft housing, remove and replace the DRIVE gear, re-install everything.

** BE SURE you VERIFY the rear end ratio & get the correct speedo gears !!

2-3-4) Too much BS to deal with. Buy a replacement cluster and save your original for parts if needed. A V8 car requires a V8 Tachometer. A V6 cluster will plug right into a V8 dash and everything will work normally - except the Tach. ( You MUST use a V8 Tach with a V8 Engine ) If your original Tach worked OK then just swap in it. ( & be thankful because they are almost always off ! )

P.S. You can't use any factory mechanical Camaro speedo system,... anything mechanical would be aftermarket.

 

Awesome thank you very much for the info.

I hope I just need to change the driven gear then because that sounds super easy and quick. I don't remember how to verify the rear end ratio so I'll have to look that up. I know it has something to do with jacking up the rear end and spinning one of the tires while looking at the driveshaft. I don't assume the ratio would be stamped on the axle (if the gears weren't ever messed with.)

I figured there was too much wrong and I messed up more stuff when trying to fix the odometer. I found some electronic ones on ebay, so I'll have to wait to get some money and swap those in. If I go with the V6 electronic one, I'll just swap my tachometer in. As far as I can tell, the tachometer seems to be accurate. I'm not quite sure how to tell if it is off or not, but it doesn't seem out of the ordinary. Also, if I take the driven gear out, would I be able to peak inside the tail-shaft and tell what drive gear is currently installed, or I do have to take it out to verify first?

Thanks again for the info! Now I'll just try to look up what driven gear I need!

 

Did you install an after-market instrument cluster? If so, did it fit with dropping the steering colume>

 

Sorry about the late response! I have not had much time with engineering finals and work picking up. Anyways no I have installed an after-market instrument cluster. I did take mine out a couple times to mess with it, and I only had to set the tilt wheel on the lowest setting. I believe an aftermarket one would be the same amount of work, so no dropping the column for that.

I still need to fix the speedometer issue by purchasing a whole new unit, but I have been dealing with a possible distributor/fuel pump issue and a transmission issue.

I just found out that my input shaft tip is horribly worn, so I have to figure out how to fix that...