4x4 Transmission torque rods - Big block specific

[Craig 85]

I recently purchased my 85 K30. It has a 454, TH-400 and a NP-205. I noticed the driver side torque rod is not present, but based on dirt and grease near the motor mount, it looks like at one time it may have had one. (Truck has been off the road since 1998). It does have the mount that goes from the trans to the transfer case.

The truck has an aftermarket chrome oil pan that some put on. I noticed that the oil pan on my 79 K15 with a small block has a taper on the driver's side that allows the rod to fit. The aftermarket pan on the 454 does not have this feature and is more square on the corner.

I test fit the left rod off my 79 and it looks like the rod will fit if I slightly bend it (about 3/8-1/2"). I can get a torque rod from Pick and Pull, but I'm just wondering if factory big blocks had this driver's side rod?

 

[1991V3500]

I've got a 91 v3500 with a BB and 4L80E and it only had one on the pass side. I removed it to run the headers and exhaust system. I can check tomorrow and see if there is evidence of rod on driver side.

 

[Rusty Nail]

Sweet score Craig.

 

[HotRodPC]

How long is this rod on the left side? I'm not aware of any having the rod on the left side, though I don't recall seeing a BBC in a 4x4.

What I've seen is the long rod Kelly mentions on the right side that goes from the bellhousing bolt to the transfer case. Then 2 short rods that come off of the heavier aluminum torque converter cover to I forget where on the block somewhere. I'd probably call them some type of short strut rods, then the 1 long torque rod on the right side.

 

[Craig 85]

The driver side rod is 16.5" end to end. It is the short one that goes from the motor mount to the transmission inspection cover. The passenger side has both, engine to trans and trans to transfer case. My 79 small block K15 has these torque/ strut rods on both sides of the block.

As far as I know K30's are the only trucks that have a big block and 4WD.

 

[Craig 85]

Sweet score Craig.

Thanks. I've purchased a bunch of parts for the restoration. I just need to sell my 79 K15, so I can start the 85.

 

[Handy Andy]

not trying to hijack your thread, but anyone have an official name for these torque rods? or a part number? During my engine swap, we noticed these were non existent on my truck and I figure since I've got about 5k into my motor and new transmission it might not be a bad idea to get these things and install them... truck is an 86 gmc k1500.

 

[Craig 85]

GM calls them a Mount Brace. The left is GM 15529883 and is still available. The right is GM 15529884, but is discontinued. You need Part #7 for both sides. They are unique to each side and attach at the motor mount location. I don't have the part number for those. You need the correct cast aluminum inspection cover for the transmission, so the bars have a place to connect to. Lastly, there is a third torque bar the goes between the transmission and the transfer case. My 79 K15 is in the shop and the K30 does not have the bars installed right now or I'd take some pictures.

http://www.gmpartsdirect.com/oe-gm/15529883
http://www.gmpartsdirect.com/oe-gm/15529884

 

[Handy Andy]

GM calls them a Mount Brace. The left is GM 15529883 and is still available. The right is GM 15529884, but is discontinued. You need Part #7 for both sides. They are unique to each side and attach at the motor mount location. I don't have the part number for those. You need the correct cast aluminum inspection cover for the transmission, so the bars have a place to connect to. Lastly, there is a third torque bar the goes between the transmission and the transfer case. My 79 K15 is in the shop and the K30 does not have the bars installed right now or I'd take some pictures.

http://www.gmpartsdirect.com/oe-gm/15529883
http://www.gmpartsdirect.com/oe-gm/15529884

Thanks Craig. I have the correct cast aluminum inspection plate but it is cracked so the guy that is rebuilding my transmission is going to find me the inspection plate. I also already have the bar that goes from the transfer case up to the bell housing. I'm just having a hell of a time trying to find ANY kind of information on those torque struts that are specifically for my truck and all the guys I know who love these trucks like I do don't seem to have a clue what I'm talking about. I'm thinking I may just have to fabricate something up. Oh well, guess I have a reason to go buy a welder!

 

[Craig 85]

Before my 1/2 ton went to the shop, I compared my two trucks and the bars were the same truck to truck. The 79 has a 350 w/TH-350 the 85 has a 454 w/TH-400. I'm only having an issue on the 85 due to the fact that someone put on an after market oil pan and I'll have to bend the left bar just a bit. Hopefully you can get the parts from a local truck. If not, try Bill at Vintage Chevy Trucks. He parts out insurance totals and sells the parts. Here's one of his Craigslist ads. Really nice guy.

https://sfbay.craigslist.org/eby/pts/6011828524.html

 

[Handy Andy]

Yea so after looking at it some more I think i'm for sure gonna have to just make something up myself. After market headers are pretty much directly in the way of this thing so I'll have to just fab something up. Thanks for the info guys!