Correct speedometer cable for 79 400 with Super T10 4 speed.

[Seven]

What is the correct length speedometer cable for a 79 400 4 speed?

[b_hill_86]

Exact length? Not positive but I believe 80” is available and will work. I want to say the cruise version of the lower cable is 60-something inches.

[wheels78ta]

GM #88959477 replaces GM #25033161.  I haven't found any measurements for #88959477 so not sure about the length.

https://www.ebay.com/itm/166224599245?autorefresh=true

[nUcLeArEnVoY]

Many '79 400 4-Speeds were equipped with a two-piece speedo cable, with a Stewart Warner brand reducer gear in between them. That's how mine is.

I do know that the lower cable that goes from the trans to one side of the reducer is around 17" or so, and the part number is 6480244. I grabbed a NOS AC one when I had to replace my speedo cables.

The upper cable that goes from the other side of the reducer to the speedo itself, I forget the GM part number but the Pioneer CA-3009 is a direct replacement.

I can check to see the type of reducer I have as well, if you like.

[Seven]

I'm finishing up an engine out mechanical refresh on the front half of the car.  It has a two piece cable in it, however its much too long.  There's a big loop in it and the gauge bounces at low speed.  I'd definitely like to replace both the upper and lower portions as long as I'm this far into it.

[nUcLeArEnVoY]

I'm finishing up an engine out mechanical refresh on the front half of the car.  It has a two piece cable in it, however its much too long.  There's a big loop in it and the gauge bounces at low speed.  I'd definitely like to replace both the upper and lower portions as long as I'm this far into it.

You're always going to have a little bit of bounciness up to around 15 mph. Mine does the same thing and I have all new cables of correct lengths. The only other thing that could be causing the bouncing is the reducer. Routing the speedo cables is a little challenging if you have a true dual exhaust since the factory routing will cause it to be too close to a driver side exhaust headpipe for a true dual. The original exhaust system didn't have any pipes even close to the speedo cables on the driver side. 

[wheels78ta]

Is the one piece speedometer cable for the W72's only?  I ask because mine is W72 and is a one piece.

[nUcLeArEnVoY]

Is the one piece speedometer cable for the W72's only?  I ask because mine is W72 and is a one piece.

My car is a W72 and is a two-piece, as originally equipped. The consensus I've made is that some were produced with two piece cables, other with one piece.

[tinpusher]

My 79 400/4 speed has the two pieces cable.

[wheels78ta]

Maybe Van Nuys vs Norwood?  Mine is Van Nuys.

[Seven]

I purchased an original GM 6480244 cable from GMpartsgiant.com.  It included both sections.  The assembly manual seems to indicate the cable runs over the top of the transmission.  It shows two cable clips, but doesn't give a good depiction of their location.  Where should they be mounted?

[roadking77]

Thanks Ben, Every time you make a post I find more stuff I need to get 

I have the 80 assembly manual I will have to go back and look for that page. I thought they also showed the 2 piece with the adapter for the manual transmission?

[Seven]

Sorry, no pictures.  My clips were missing, and the speedometer cable changed from the original at some point along the line.  The clutch I removed was marked as rebuilt, so everything was probably changed when the clutch was replaced.  The excessively long cable was just draped across the top of the transmission and not held in place by anything.

 I have two of the 477704 clips as shown in the 1976 AIM, and the picture looks like one of the clips is mounted to one of the transmission bolts.  I can't make out the location of the second clip? 

The cable enters on the passenger side of the transmission tail shaft housing.  The pictures for 1980 probably don't apply, as there were no manual transmissions available that year, and both of the images show the cable attaching to the drivers side of the (automatic) transmission.

[wheels78ta]

The 4 speed cable runs underneath the transmission...................

[roadking77]

Thanks Willie, That helps.

[nUcLeArEnVoY]

Here's a photo of the routing on a survivor car that still uses factory exhaust. This uses a two-piece cable.

Bear in mind that for a car converted to dual exhaust, you'll need to think of a way to keep the cable away from the headpipe since it will be very close to it. And when routing the cable, try to sort of allow it to lay out along its "natural" curving bias. Any acute bends or kinks will lead to a quick cable failure - ask me how I know.

[roadking77]

Thanks for the pics. I was grabbing my radiator off the shelve from its perch of 5 years now and found a box of stuff that a fellow member gave me awhile ago. I opened it to find a complete wiring harness -dash and engine bay, and a couple of bags of clips and fasteners. Among them were clips for the speedometer. Without this current thread I would have had no idea what they were for. There was also a clip for the oil pressure wire that bolts to the bell housing. Another one I would have had no idea where it was from had Ben not mentioned and sent a couple off to me.
Thanks again to the knowledgeable guys on TAC.

[Seven]

Many thanks for the pictures and comments.  They way my car was set up was completely different than the picture above.  The clips and installation make sense now.  Bubba has left the building...

[sreta]

Here's the clip

[Wallington]

Here's the 1972 diagram, it was still dual exhaust. It shows the earlier clip than photo above.

Screenshot (76) by Ben, on Flickr

[sreta]

What about this one ?!

[Wallington]

Have seen that ad before. Usually Jim the seller is excellent but I think he is confused here. Looks like 301 A/C line bracket. But it's not my area either.

Here's some alternatives now reproduced.

https://www.firebirdcentral.com/1967_1981_Firebird_Speedometer_Cable_Clip_p/das-321.htm

https://www.firebirdcentral.com/70_79_Manual_Speedo_Cable_Clip_Tail_Shaft_p/tra-161.htm

Here's the alternative version of the #477704 speedo cable retainer shown in Sreta's sample photo above the diagram post. It features a little tang added so that it didn't swing down with the weight when fastened off the trans instead of chassis rail. Fits either location but modified for the latter. Possibly what is seen in Willie's 2 pics, hard to see if had tang added yet.

I think their calling it #9772827 may be incorrect. It doesn't feature in parts manuals over the era that it was used, while there was already an existing part using the same number from early 70's GM, a white plastic/nylon insert for hood cable guiding.

https://www.firebirdcentral.com/67_81_Speedo_Cable_Clip_at_Bellhousing_9772827_p/tra-162.htm

https://garbee.net/~cabell/december/datcon/~hpa0000.jpg

[roadking77]

Does anyone have the part no. for the stewart warner reducer?

[nUcLeArEnVoY]

Does anyone have the part no. for the stewart warner reducer?

#368026 is the part number,  but for functionality you're better off searching for one by the correct ratio that it reduces - 1.3000.

Looking up items for sale by the part number doesn't get you any results, but looking it up by the ratio you'll find some examples on eBay. An original is supposedly stamped "BH" according to the service manual.

*Oh, and quick off-topic bit of info regarding your past heater hose topic (didn't want to resurrect it since it's old, so I'll just respond to you here lol): As established in the thread, correct heater hose has the ribbing, but the hoses should also be stamped along the length of them with the corresponding codes shown on your build sheet, at least on Van Nuys built cars like mine. My car still had the original hoses on it before I revamped the cooling system. Box #'s 51 and 52 will show the inlet and return heater hose stampings respectively on the build sheet, and those characters are stamped along the length of the hose roughly every 8 inches or so. For  instance, my inlet heater hose was stamped "KK" and my return was stamped "HG."

Just wanted to let you know in case you're going for a correct resto.

[roadking77]

Thanks for the info. It will go to good use.

Reason I asked about the reducer is that I have one on another motor. By pure coincidence, I was in my small shop the other day where I have a 283 stored. The reducer is on the transmission! From what I have found they were not all that uncommon but most were attached directly to the transmission. This thing on the trans am with 2 cables seems to be the exception. I did not look for a number yet but wasnt sure if by chance it would be the same thing. I am pretty sure I will just go with a one piece cable though.