Kenworth T800 rear engine mounts

[Andre_The_Giant]

Last weekend I changed the rear engine mounts on my 06 Kenworth T800 with an ISX engine. It took me about 4 hours from start to finish. I wanted to share my experience with others, and hope to help anyone attempting to do this.

None Common tools I used-
-30mm DEEP impact sockets ( 1/2" drive & 3/4" drive)(6 Point)
-30mm combination wrench
-1" & 3/4" impact gun
-Impact adapters, 3/4"-1/2" & 1"-3/4"
-Multiple sized impact extensions
-standard 20 ton bottle jack
-old brake drum and blocks of wood

I started by removing the bolts, you don't need to support the engine at all while removing them. It will not fall, even with the bolts completely out.. All of my impacting was done from below, with the combination wrench on top. I used the frame to hold the wrench up top, while paying close attention to the way it would spin (what it would hit).

The driver side was the most intimidating. There are a ton of wires/hoses along the frame rail that made it extremely tight. At one point i didn't think I could even fit a socket on. But you definitely can! I had to use a thin walled 1/2" drive 30mm, with an adapter to the 3/4"impact. The passenger side has more room, but was stuck worse for some reason. I had to use the 1" impact gun on it. After i removed the lock nuts, the bolts pushed right up and out for me (Luckily)!... I had a small Air hammer tool on standby and recommend you do too, in case they are sized in the old mounts.

Once the bolts were out, i placed the old brake drum, a couple pieces of wood, and bottle jack underneath.. I did not know where to jack it from. Jacking from the rear engine ears did not give me enough room to slip them out. What i found worked was jacking up from (what seemed like the most solid) rear part of the transmission. Pay VERY close attention to whats going to move upwards. I had to disconnect the drive shaft because it was close to hitting a cross member. Disconnecting the drive shaft was easy, just 4 bolts on the U-Joint caps and it pried right off. Be sure to support the shaft with a bungee cord, so it doesn't fall and hit the ground. I had to jack the transmission up quite a bit, i could hear my exhaust flex pipe bending (it made me cringe). But that's about it.

Once the old mounts slipped out the back, the new ones slipped right in. I lowered it down slowly and covered the new bolts with anti-seize. I couldn't find a torque spec anywhere, so i used the 3/4" impact to tighten. Hopefully i didn't over torque them :-/ But finally no more clunking! lol

Some things to worry about - you may have to cut or torch them out from what i hear.. If your bolts look extremely rusty, i would have a torch ready.
- Try to avoid removing the 4 bolts on the engine bell housing. I think it calls for red loc-tight and its only an aluminum housing. If they must be removed, heat the heads with the torch to loosen things up a bit.
-Also as mentioned the bolts may be stuck in the old mounts so you may have to air hammer them up and out.

Here's what mine looked like, hope this write up helps