I believe my starter is dragging. I have gone through everything I can think of to avoid removing it, but that's what I had to do. It is a 40 MT, I have it off now, but it was really difficult. All three bolts required a cheater bar to start. One required multiple bars totaling over six foot and a lot of time trying. When it comes to reinstalling it, should it be cheater bar tight? I have a 150# torque wrench, but I am not even sure I could get it in place for all three bolts.
What grade, size and thread type are the bolts? If you have that info, we can find a torque for you.
Brian
Brian,
I do not know that info exactly. I assume that they are special for this application. They are 5/8 bolts with a collar and then a 5/8 12-point head. I am sure that they are hardened. Otherwise, those cheater bars would have done some real damage.
They are probably around the same as SAE Grade 8, or possibly SHCS (socket head cap screws, otherwise referred to as "Allen" bolts). A torque around 180 ft lbs is probably adequate if the bolt threads are fairly dry, if lubricated about half that. Torque call-outs often have specific lubrication (or lack thereof) requirements, what you really need to do is to stretch the bolt enough to make it lock in place and resist vibration. The real goal is to stretch it to create a load of 75% of it's failure load.
Holo-krome (a high quality SHCS) calls out 283 ft lbs for coarse thread, 317 ft lbs for fine thread, SAE grade 8 212 ft lbs for coarse, SAE grade 5 186 flt lbs for coarse. I am suggesting a little lower because the threads are probably not going to be perfectly dry, and you probably aren't going to have perfect washers under the heads and all that.
if you can find a number in a manual, all the better. In the real world, people have just been doing them up as tight as they can and calling it good for forever.
Hope this helps a little bit, anyway.
Brian
Lin,
That cheater bar stuff sounds like too much to me. Anyway, bolts/nuts almost always take a lot more torque to remove than to install.
Any 2-stroke DD book should have the starter bolt torque specs.
I presume this is a 8V71??
Gus,
Usually I assume the the bolts have become harder to loosen with time. However, since I know that the starter was off about 300 miles ago, I was wondering if they had been made that tight on purpose. I guess I will get them as tight as a can with the wrench and then just add a little more for good luck.
My 671 maint manual starter section says it is a 5/8"-11 bolt which takes 137-147 lb-ft. If it happens to be a 5/8-18 it takes 169-178.
These specs are for anything above grade 5 which, I'm sure, includes all DD bolts.
Torque specs are a lot different with an extension. I always go by the rule of "goodntight" on application such as this. You will be fine. Just use common sense.
Chopper,
Extensions don't have any effect on torque specs, torque is torque no matter how you do it.
Sorry Gus but you are wrong. Not trying to start anything. Just don't want wrong advise being given out.
settle down, we need a definition of "extension" before you two start hurling...
Lin, with the suspected abuse you describe, give those bolts a little clean off on the wire wheel, then run them into place by hand before putting the starter up, to be sure they go in easy and smooth.
You want to be sure the threads are not damaged. If the bolts don't go in nicely, you want replacements, and/or a tap to run the holes.
happy coaching!
buswarrior
BW,
I will run them in and out first as you suggest. I think they should be alright since, once broken and loosened a couple of turns, they did turn easily by hand.
Lin,
When I installed my starter 3 years ago I just used a wrench and got it as tight as I could. One bolt at the rear was a real pain to get to. It hasn't fallen off yet. ;) Just get it as tight as you can, you should be fine. The hardest part was lifting it into place! ;D
When you are not sure of or cannot torque to spec, the best course of action is to recheck regularly. Amazing how many other problems you can head off when you snoop around on a regular basis.
Good luck
Don 4107
Quote from: Dreamscape on July 28, 2010, 05:02:50 AM
. . . . .Just get it as tight as you can, you should be fine. . . . .
Be careful following that advice. Tapped holes in cast iron will strip out.
What you want to do is get as close to the specifications (found in the proper manual) as practical. We all know what too loose or over tightened will do - sucess lies with the number in da' book.
My guess as to why they were so hard to get off is that the threads are dry & are slightly distorted from previous abuses which ads to the friction retaining it.
You won't necessarily need a torque wrench, but you should get them properly tightened but not over tight.
Have fun! ;D
Thanks for the help. It is back in now. I tightened the bolts as much as I could with a standard 3/8" ratchet. I doubt there is any way my puny self could have over-torqued it with such a small tool. I did give them a little snug with a small extension. I will monitor them too see if they begin to loosen. Normally, this would not have been a question, but since that had been put on so tightly just a few hundred miles ago, I thought that maybe that was required.
Anyway, after trying to trace the starting hesitation through the whole system, I finally got to tackling the starter, which was the problem. I was pretty sure of that when I noticed that one of the lead battery terminals was melting probably from a ridiculously high amperage draw. I started it up a couple of times to test it, and it sings. Maybe we can get some trouble free use in for a while now.
Would a "Thread lock" type product made it that hard to get out ??? JIm
It all depends, there are many types of thread lockers for many sizes, uses and temps.
Quote from: jjrbus
Would a "Thread lock" type product made it that hard to get out ??? JIm
Quote from: gus
It all depends, there are many types of thread lockers for many sizes, uses and temps.
What Gus said! As long as "Loctite" and other such products are properly matched for their intended application they are great! What is a real PIA is when someone uses the wrong stuff and it can actually cause damage removing a bolt after word! They make all kinds and all have labels saying the size bolts, intended torque range, heat range, as well as a general use description! Use the right stuff and "no worries!"
FWIW ;D BK ;D
Some thread-loc compounds require heat (up to 500F) to safely remove.
Just to keep things straight, these bolts did not have any thread lock on them. The person that tightened them said that he is sometimes known for getting things really tight.
I'd be really hesitant to put any thread locking compound on starter bolts.
How you gonna get 'em out next time?
There are precious few places a busnut needs to resort to Loctite.
The 4 little screws for the fan on your big air-cooled Delco might be one place... but otherwise, best go real easy with that stuff.
happy coaching!
buswarrior
Some loctite requires very little torque to loosen, it all depends on what you use. It is never a good idea to just pick up a tube and use it without knowing its specs, there are many, many different kinds.
I think loctite is very useful because these old guys vibrate so much, stuff is always coming loose on my oldie (1954).
I have a stout son-in-law who can install nuts I can't get loose, he probably breaks a few along the way!!
I was happy to read this thread as I have to have my starter pulled for rebuild. Unable to do it myelf as I just got out of the Hospital with a brand new complete left hip on Saturday. But after it's been repaired I'm hoping to do the re-install. I'll be able to put a lot more torque on that mammy-jammer now!
NCbob
Quote from: NCbob on August 01, 2010, 10:01:58 AM
I was happy to read this thread as I have to have my starter pulled for rebuild. Unable to do it myelf as I just got out of the Hospital with a brand new complete left hip on Saturday. But after it's been repaired I'm hoping to do the re-install. I'll be able to put a lot more torque on that mammy-jammer now!
NCbob
;)
Bob glad to hear from ya again, good luck and great to hear you'll be get'n around better soon too!
;D BK ;D
Bob,
Hope your recovering goes well. I really was not sure I wanted to do the R and R on the starter, but cheap as I am, I did it. It is easy to get to and straight forward but heavy. I sometimes contemplate whether it is better to pay a mechanic or a doctor. Anyway, it was decided for me since the local auto electric place's price for starter and labor were out of line, so I removed it myself to take it elsewhere. Anyway, at least gravity was on my side in the take out. Putting it back was different. I used a combination of a sling and levers to get it in, but if you have a floor jack, it would be much easier.
Unless you are 20 year old line backer, rolling floor jack is very necessary tool for reinstalling starter ;D JIm
At the risk of sounding like a one-trick pony let me again put in a plug for the Delco 39MT series of starters. I can't actually one hand mine at full arm sideways extension but I'm sure some of you could.
39MT is great as long as you have a right handed rotation engine. At Freightliner, the servicing of these jewels is alot more frequent then the old MT41 or 42. If you can heft the weight, I would stick with the old tried and true MT41. Good Luck, TomC