Oil dipstick. Looking for education before i proceed

LQQKatJon

Well-known member
Oct 22, 2010
3,234
559
113
St. Cloud, Mn
lqqkatjon.blogspot.com
Helped a friend pick up a Gmc this weekend. It seems his 455 eats the last 2" of oil dipsticks. The po had some issue with dipstick not going in
before we picked it up, but he fixed it. I checked the oil fine once, but second time I pulled the dipstick out, the flat bottom couple inches
were missing. This was done with engine running because we has a starter issue and did not want to risk turning it off at that location. I did not
force the dipstick either.

When i got home, i pulled my dipstick out that has been an issue on my coach for some time and only goes fully into the tube when turned the right
way.

I put that dipstick into the new coach(this time engine off). Snd when i pulled it out, the bottom 2 inches were missing on mine!

Anyway, looks like i have two 455's to fix the oil dipsticks on. I have seen Ken H's great pictures and just done sone quick reading. His pictures
are good, but are engine with oil pan off and pulled from coach

What should i know about replacing dipsticks and tubes so i have trouble free oil level checking into the future. My coach is a 75 and looks to have
a 1 piece tube with stock exhaust manifold, The other is a 77 and looks like there is a joint in The tube(2 piece) and has headers.

Thanks.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
Ok. Finally had some time to read.

Can dipstick tube be changed without removing exhaust manifold or header?

I believe mine has a bad bend at exhaust manifold, but otherwise is ok. I think i can fix that.

On the 77 that ate both dipsticks, i will have to get a better look at that one as far as what is the problem. It has headers.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
Jon,

In years of being a engine test rat, the universal reason for dipstick breakage has been interference with the crankshaft. If it was a prototype
engine, that is not good, but it is forgivable. For it to happen on an engine with manufacturing history, is not something that happens without real
good cause. The only times I have seen it on a production engine were when someone screwed up the assembly and put in a tube for a different version
of the same engine.

The only thing I can imagine is that there is something very much out of place to break your stick in a single event and with the engine shut down??

I will forego asking questions, because the only way you are going to figure out what happened will be to go in there with a camera. There is
obviously something interfering with the dipstick's path and it pretty much has to be the tube itself. For yours to go in without serious effort and
then break, is a scenario that I can't get my arms around.

Do you have a friend (nearby) that has acquired one of the new little endoscopes? I could not organize shipping mine before we have to depart foe
Mansfield.

You should be able to dump the lube oil on the dipstick eating engine and go magnet fishing on the pan to retrieve the broken part. First bet, you
find more than two. Second bet, it will be a pain and will be messy. Believe it or not I did this once, only because the client demanded it. The
piece always came to the hole positioned so it would not come out. With two forceps, I was able to walk to one end and put the part out.

You are going to have to keep us informed on this one.

Matt
--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit
 
I will let you know how it turns out. Need to pull that drivers wheel well liner and change out the tube to start with. It is sounding like
Chances are, it has an incorrect tube installed when they put the headers on.

Hopefully parts will be here by the weekend, I think I will be able to drain the oil(need's oil change anyhow) fish out the old pieces. add the
correct amount of oil to get through the week.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
There is a very narrow space directly under the hole in the side of the
block that the dipstick goes into and just touches the bottom of the oil
pan. Nearly straight down, and the correct dipstick tube is quite long to
direct the stick safely out of harms way. If your tube only goes a short
distance beyond the casting hole, then you do not have the correct tube,
and the dipstick can make contact with the crankshaft and rods. Not a good
thing. With all the changes in exhaust manifolds, cylinder heads, Headers,
Remote dipsticks etc., it is a no brainer that the wrong stuff often gets
used after 40 years of engine swapping and clueless people working on this
stuff. The same thing happened to me once with a new engine I was
installing for a customer. I pulled the engine back out and removed the oil
pan to see what was what. Never made that mistake again. The hole in the
block just fits the O.D. of uncoated fuel line tubing, but it fits too
loose and slops around and leaks oil and does not stay in place. I use
coated fuel line that is made for alcohol blended fuel and carefully form
it into the exact same shape as the factory tube. When I have it exactly
the same, I carefully sand the coating off a bit at a time until it just
will go into the hole in the block by hammering it into the hole. I seal it
with "the right stuff". If you look at the stock manifold that GMC used on
the coach, you will notice a clearanced spot for the dipstick tube. Headers
do not have that clearance, and many people place the tube outside the
header flange. It has no support there, and has the wrong angle inside the
pan. That brings the dipstick into contact with the crank, too. Simple
stuff, but important details. Guys that know these GMCs are mostly aware of
these pitfalls. There are more of them, like the hole drilled in the cam
plug in the rear of the block to lube the distributor gear. Rebuilders will
sometimes put a blank plug in there. Good bye distributor gear.
Jim Hupy
Salem, OR
78 GMC Royale 403

> I will let you know how it turns out. Need to pull that drivers wheel
> well liner and change out the tube to start with. It is sounding like
> Chances are, it has an incorrect tube installed when they put the headers
> on.
>
> Hopefully parts will be here by the weekend, I think I will be able to
> drain the oil(need's oil change anyhow) fish out the old pieces. add the
> correct amount of oil to get through the week.
>
>
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
 
I am almost done with my Dipstick project on my friends new to him Coach.

Pulling the wheel liner, and removing the drivers side tire, I got in there to take a look. The dipstick tube was broken off right at the block. I
was also able to find one broken dipstick end sitting on top of the transmission, so I am now thinking the other end that broke off a 100 miles south,
might be on the road somewhere. I still confused at how easily it broke off, because I did not force it in and out, but the dipstick I was working
with was the wire type, with the flat part at the bottom, and it broke at the transition, so that could be a very weak 40 year old point.

I lucked out, and yesterday on my way home, I stopped at a "tools and more" store and bought a $25 slide hammer, because that is one tool I have
never owned, and the slide hammer I bought actually came with a GMC dip stick removal adapter. one of the ends, is a EZ out type adapter, that is
the perfect size to go into and grab the dip stick tube.

http://www.gmcmhphotos.com/photos/how-to/p61396-dip-stick-removal.html

Installing the replacement tube was more of a chore then removing the old one. I am hoping it is all good, and I cannot figure out anything I could
of done different to effect how the tube went in and where it ended up once it is in place. The tube hammered in very tight. I ended up taking I
think a 7/16 nut, and welding a long steel bolt to the side of it, and sliding that nut over the tube, so I could hammer down right on the ridge of
the new Dipstick tube that is where it sits against the block. but I the last inch or so I had to adjust because the nut was hitting the block. It
just was a slow process, with a little more force then I would have liked. I do not see how I could of installed it wrong because of how tight and
the only way to get it to go down that hole, was straight direct force downward toward the hole. If I have to do another, I will probably fabricate
a little better tube installing hammering on device. I seen one on DJ's site, and that I would think would be a good method, but I had no scrap
tubes in the garage of that size:

http://www.djsgmc.com/NewParts/LowerDipStick.html

So new dipstick tube is there, It had headers, so I was able to do the job without removing the header. I think there is no getting around needing
to remove an exhaust manifold to do this job if you have to do it to a coach with manifolds. I had to pick up a compression ferrel to finish up the
joint to the upper tube, and will be testing it tonight.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/