shaking my doors off

[BJMarshall]

Just a couple of things here. I have 2 first gen trucks. The one I drive and a parts truck. When I shut the engine down on the my daily driver, it feels like it is going to shake my truck apart. The parts truck stops so fast when you shut it off, it squeaks the belt. Why?

I finally got up the nerve to bump the timing up a little last night. I got 3/32 between the marks. I couldn't move it a full1/8. It didn't make any difference on the way it shuts down, but WHOA NELLIE did it change the power. EGT's are down even more as well. I checked the fuel pin, and it had already been turned to its deepest spot. I went ahead and turned the starwheel 1 turn. It is like driving a whole different truck.

I put a few pictures of the Intercooler swap in my gallery if you are interested. I don't want to hear any crap about my parts truck looking better than my daily driver either.

 

[PaulG]

Originally posted by BJMarshall

Just a couple of things here. I have 2 first gen trucks. The one I drive and a parts truck. When I shut the engine down on the my daily driver, it feels like it is going to shake my truck apart. The parts truck stops so fast when you shut it off, it squeaks the belt. Why?

compression of the motor so when you shut down the motor stops faster than the belt can it is common for all of us.

 

[jandtjil]

I actually like belt squeak Reminds me I am driving the truck I wanted, not almost what I wanted.



JJ

 

[BJMarshall]

Why does one truck do it and the other doesn't? Is something wrong with one of them?

 

[jandtjil]

Belt tension maybe. .

 

[BJMarshall]

I'm not worried about the belt squeak, I want to know why they shut down differently. One stops immediately, so fast it squeaks the belt (which I don't mind), and the other one shakes violently as it slowly comes to a stop.

 

[BJMarshall]

I think the belt squeak is kinda neat Always makes people turn and look.

 

[jandtjil]

Sorry about that, I just reread your original post.

Never experienced shaking on shut-down. Had mine shake like a hula girl with an ice skirt once, after changing a fuel filter and losing prime to a couple injectors. I thought the hood was going to come off the hinges. :--)





I'm stumped!

JJ

 

[BJMarshall]

That's kinda how mine does, but every time I shut it off.

Hula girl with an ice skirt? Good one

 

[cerberusiam]

Motor mounts and/or retarded timimg will cause the "wet dog" shake on shutdown. You need to verify timing is advanced by putting agauge on the pump as the marks were not always correct.

 

[bgilbert]

I have the same problem/deal. My early 91 shutsdown immediately. My 89 does the wet dog shake at shutdown. We being non-intercooled already have advanced timing to an extent, at 1. 40mm. I even tried to advance my timing on the 89 maybe got it 1/32" anymore and it pinged, but it still does the wet dog shake, I'm thinking along the lines of loose motor mount, I think my driverside mount if bad, hmm need to get that fixed...



Btw BJM, the truck in your RR's was that the donor? You were non-intercooled to begin with right? I kept looking and was saying that sure looks IC'd to me- t-stat housing, intake horn etc. Sorry to hear you had a rough time getting advise from members on the IC swap, if I could've helped, I would have.

 

[BJMarshall]

Yeah my 91 was non IC. Most of the pictures are from the donor. I stuck another one out there of mine. The pic with the intake off is my truck. This was the main thing I wish I had known. I didn't have a new gasket so right now I have silicone on the intake. It doesn't appear to be leaking though. I was just venting a little I guess. Sometimes it seems silly that there is a 500 post discussion going on about what type of polish to use on your exhaust tip, and you can't get but 2 or 3 replies to a legitimate mechanical question.

I like how this is being described as the wet dog shake. That's exactly what it feels like. I am trying to make sure I don't cut it off with the doors open. I think I am going to take it in to the shop next week and have them go over it. At just over 250K I am sure it wouldn't hurt to have the injectors cleaned and tested and have the overhead done.

 

[BJMarshall]

Bill

Mine that shuts down immediately is an automatic. Looking at your RR, your automatic also appears to be the one that stops quick. You think that may be what it is?

 

[sparks57]

Shaking the doors off? My subwoofer does that!



Just kidding, but my truck shakes hard when I shut down, no big deal.

 

[bgilbert]

BJM, yep never thought of that auto vs stick. This has got me wondering now.

you can't get but 2 or 3 replies to a legitimate mechanical question.

I hear ya, I've been there. This site is good though, we have members that specialize or know more about one thing in general such as getrag, engine, auto, bombs, etc, just sometimes what we're looking for hasn't been covered in the archives and the guy that has BTDT isn't available. But I still love the TDR!:d

 

[BJMarshall]

I love the site. No complaints. I have gotten enough information from searching the old posts to offset the cost many times over.



I was just looking through some old posts about the shutdown thing and someone said that it may be because the flywheel and clutch assembly weighs more than the torque converter thus having more stored energy. Just a thought.

 

[dpuckett]

My pickup does that now and then- the violent wet St Benard shake. It always shakes a litle bit, but then it takes 3-4 sec to finally wind down. So, that leads me to believe it may be fuel system related, like the shutdown solenoid isnt functioning quite up to par? Maybe timing after you hit the key to OFF, and it retards itself big time? I had a 92 that did that, got the pump rebuilt, because it vibrated at idle, too, and it didnt change a thing. I really dont know. The 88 INternational with a 350 BCIII I'm fixing to start driving again shakes like a wet dog on shutdown, too. I mean, almost break windows shake. Dont worry about it if it has always done it. If it is new, it may be worth investigating.



Daniel

 

[BCook1]

Pro timing set.

After having a professional diesel shop set my timing to the max factory setting, the shut off shudder was dramatically reduced. Don't trust the marks - mine are more than a quarter inch apart - two shops set and checked the timing for correct max. The diesel noise at idle is much louder now.

 

[BJMarshall]

The noise at idle definitely increased when I changed the timing. I got to drive it tonight for the first time unloaded since I made the change. I had about 8000# behind it when I made the change. I knew it was better, but I didn't realize exactly how much. WOW