727 Trans Speedometer Gear

[khryslerkid]

It looks like you're good down at the trans.

I've seen replaced cables that turned out to be too short, if it was replaced in the past.

You have to make sure of the lenth by removing the housing from the speedometer and see how much cable is showing. Has to be enough to engage into the speedometer head when assembled and all tightened up. With the cable removed from the speedometer, push the cable into the housing and try to turn it. You shouldn't be able to because it's engaged into the gear down at the tail shaft. Take notice to how much cable is showing. Do the math and make sure there is enough to engage the speedometer head properly. You can also pull the cable from the housing on this end, for a visual inspection. A prominent square shape on each end of the cable is important also.

The other thing to check for operation is to put a drill on the transmission end of the cable, with the cable hooked up to the speedometer. Turning the drill in one direction will be like running the car in reverse and you won't get any reading. The other direction will show needle movement. I don't remember which direction on these anymore. Something tells me counterclockwise. You have a 50/50 chance at getting it right!

No results on any of these checks will be a problem with the speedometer itself.

 

[oldbee]

KK good thought.

 

[Mr. Belvedere II]

B-II I understand ur getting upset, you need to sit back and think over everything from the beginning. From what I see it should work, recheck everything and get back to us.

Oh I'm not upset, I've been driving without a speedo for like 7 years lol. It would take a lot more for than this to upset me! I'm just baffled is what it really comes down to!

 

[khryslerkid]

Oh I'm not upset, I've been driving without a speedo for like 7 years lol. It would take a lot more for than this to upset me! I'm just baffled is what it really comes down to!

Process of elimination Mr B. Think simple things first. That's two tips from an old wrench bender!

You're doing fine, and not afraid to get your hands dirty. I can tell already that you have a nack for these cars!

 

[Mr. Belvedere II]

It looks like you're good down at the trans.

I've seen replaced cables that turned out to be too short, if it was replaced in the past.

You have to make sure of the lenth by removing the housing from the speedometer and see how much cable is showing. Has to be enough to engage into the speedometer head when assembled and all tightened up. With the cable removed from the speedometer, push the cable into the housing and try to turn it. You shouldn't be able to because it's engaged into the gear down at the tail shaft. Take notice to how much cable is showing. Do the math and make sure there is enough to engage the speedometer head properly. You can also pull the cable from the housing on this end, for a visual inspection. A prominent square shape on each end of the cable is important also.

The other thing to check for operation is to put a drill on the transmission end of the cable, with the cable hooked up to the speedometer. Turning the drill in one direction will be like running the car in reverse and you won't get any reading. The other direction will show needle movement. I don't remember which direction on these anymore. Something tells me counterclockwise. You have a 50/50 chance at getting it right!

No results on any of these checks will be a problem with the speedometer itself.

Hm well it worked with the origional transmission just fine, after the swap with the TCI trans I got nada. And I never changed the cable. The gear, cable, and housing are all origional to the car. The speedo jumps a short sweep when I set the gear all up in the housing and give it a spin, so if the gear would turn, I'm sure the speedo would function, there has to be some silly little thing I'm overlooking.

 

[Mr. Belvedere II]

Process of elimination Mr B. Think simple things first. That's two tips from an old wrench bender!

You're doing fine, and not afraid to get your hands dirty. I can tell already that you have a nack for these cars!

Process of elimination Mr B. Think simple things first. That's two tips from an old wrench bender!

You're doing fine, and not afraid to get your hands dirty. I can tell already that you have a nack for these cars!

I appreciate that. I have learned it all through my own expiriences with just this car over the past 12 years. I never was trying to be a "car guy" but I became one, I guess, the day I bought this hulk! Lol

What is making me scratch my head so much with this one, is it isn't as though its a very complicated arrangement here, this speedo cable and gear thing. I've seen the speedo work before, I saw it work when I spun it today, all set up but not installed in the trans. I will figure it out, you can be sure of that. And I will feel like an *** for overlooking it, you can be sure of that too! Lol thanks for the support Kkid!

 

[khryslerkid]

It must be a difference in the tailshaft or the shaft gear if everything worked before. Need to research any differences between the two trans. What did TCI say?

 

[Mr. Belvedere II]

It must be a difference in the tailshaft or the shaft gear if everything worked before. Need to research any differences between the two trans. What did TCI say?

I haven't called em yet. I was sure today I would have resolved it. But I will get in touch with them this week. I wanna wrap up this post! Lol

 

[khryslerkid]

What I'm seeing so far is the output shafts are all the same on 727 transmissions. (Pertaining to the speedometer gear drive being machined into the shaft and it's diameter plus amount of teeth.)

 

[Mr. Belvedere II]

What I'm seeing so far is the output shafts are all the same on 727 transmissions. (Pertaining to the speedometer gear drive being machined into the shaft and it's diameter plus amount of teeth.)

Hmmmm, yeah that doesn't surprise me that they are all the same. Makes sense. It's like you said, I just need to step through it all again from speedo to cable to gear and I'm sure I'll find its some little thing I've overlooked. I'll get back under there next weekend or the week after. I changed the gasket on the housing so at least it's not leaking a 2ft wide puddle every night. Ugh these cars! lol I'll tell you what though, when I run out of things to fix, I start looking for reasons to fix stuff! I've got the bug for sure!

 

[mopar 3 B]

Front on the ramps, rear on stands. Pull the cable from the trans housing and see if that gear turns. If the top side works off the cable and drill it has got to be in the bottom side.

 

[jim ritchie]

OK,you've narrowed it down to one thing,,plastic gear not making contact with pinion gear!You said it does not spin freely ,it should not spin at all.You could do this for ever ,but if you don't lift rear wheels and run in gear( oil should not come out ,if level and run slow) now look to see if shaft is turning,with gear installed, and cable removed,then you will know FOR SURE! If it does NOT turn ,you have wrong crown gear to match pinion gear.These problems can upset us.but don't have to ,if you go through the right stages to solve them.CHEERS

 

[oldbee]

Fresh minds on Monday! Too much wear on adapter I.d. or shaft on pinion gear letting the teeth move out of way of the output shaft when rotating?

 

[Mr. Belvedere II]

Still never solved this daggum issue….. but engine and trans out of the car and about to go back in. Gonna have another crack at it…6 yrs later lol

 

[oldkimmer]

The speedo gear in the adapter is driven by another plastic gear on the output shaft. U shud be able to see it with a flashlight after the adapter is yanked out(has an o-ring to seal it)

No such plastic gear on the tail shaft. It has a spline machined right on it. Kim

 

[mopar 3 B]

I can't believe it after all this time you can't find anyone locally to help you solve this problem.