Motor Mounts

[Rodd]

I think the motor mounts are shot on the 95 sierra. While driving down the road at 25 - 35 MPH if I hit a bump just right the front end will start to shake violently. I thought it was coming from the Driver side but my friend was riding with me the other day when it happened and he said it felt like it was on the passenger side. Are they easy to replace on the 1 ton 4 x 4? How do I know if they're bad? I haven't looked at them yet.

 

[Will L.]

Remove neg battery cables (jic). Remove fan blade. Attach engine hoisting device- overhead when possible. Otherwise floor jack and 2x4 under engine. Add some kind of safety device so if it slips you dont loose fingers! R&R mount. Do both sides, one adter the other. Then before fan goes back on, do the transmission mount too. Then you are set for next 20 years.

A good thing if you can get (free rental parts stores) in your area is a tool nomally used by front wheel drive cars that spans the fenders and you support the engine from it. Cant remember proper tool name right now, sorry.


I may or may not admit to having layed 3” by 1/4” thick angle iron across fenders inside edge (to not dent fenders) and used ratchet straps to lift engine...

 

[Rodd]

Great! thanks for the info Will.

 

[Twisted Steel Performance]

Doesn't sound like motor mounts to me.. more like a pitman arm and or other front end parts....

 

[Will L.]

Yeah, I focused on changing motor mounts.
Your motor can bounce like a basketball under the hood and it won’t cause a violent shake in steering.

Jack the truck front wheels up and start checking all pivot locations.

 

[1999gmc]

Check upper ball joints and the idler arm bracket also. Just did a 97 with same symptoms you described Rodd and it ended up being both upper ball joints and idler arm bracket. He did O'reilly ball joints 4 months prior. They are junk. Napa Premium or AC Delco Professional. They usually have a blue grease boot. TRW makes decent ball joints and tie rods also. Then go get it aligned.

 

[Big T]

Remove neg battery cables (jic). Remove fan blade. Attach engine hoisting device- overhead when possible. Otherwise floor jack and 2x4 under engine. Add some kind of safety device so if it slips you dont loose fingers! R&R mount. Do both sides, one adter the other. Then before fan goes back on, do the transmission mount too. Then you are set for next 20 years.

A good thing if you can get (free rental parts stores) in your area is a tool nomally used by front wheel drive cars that spans the fenders and you support the engine from it. Cant remember proper tool name right now, sorry.
View attachment 51700

I may or may not admit to having layed 3” by 1/4” thick angle iron across fenders inside edge (to not dent fenders) and used ratchet straps to lift engine...

Will how difficult is it to get the mounts out and new ones in?

 

[Will L.]

Honestly I can’t remember. It has been a decade since I done it last. But I have never done a GM truck that got me aggravated.

 

[Paveltolz]

I think the motor mounts are shot on the 95 sierra. While driving down the road at 25 - 35 MPH if I hit a bump just right the front end will start to shake violently. I thought it was coming from the Driver side but my friend was riding with me the other day when it happened and he said it felt like it was on the passenger side. Are they easy to replace on the 1 ton 4 x 4? How do I know if they're bad? I haven't looked at them yet.

Concur with checking the steering components first. I had the bump wobble issue myself and solved it with new Tie Rods but, check it all...especially if it has been a while since you've given the system a good once over.

 

[Rodd]

I was thinking something in the steering/suspension but when I looked at them they all looked fine. I don't have any excessive wear on the tires but they need to be rotated. I think I take it to Les Schwab and have them rotated and inspect everything.