JD450b broken side frame bolts to bell housing

Digger · Post by **Digger** » Thu Mar 20, 2008 8:09 pm

I'm new to the site and it seems like you guys are willing to help if you can. My question is the right side frame bolts to the bell housing are either broke or stripped, but can not be tighten. If broke any ideas on how to get the remaining stud out? If bell housing stripped would helicoil work? I've checked the transmission case and bell housing case and they do not appear to be broke or cracked, anything else I should be looking at or for? The reason I have not tried to pull them out is because someone has welded a retainer across the top so they wouldn't pop out. I would post some pictures but have not figured that out yet. Thanks for any help.

pdmech08 · Post by **pdmech08** » Fri Mar 21, 2008 7:03 am

Digger: This is a common problem with 450's. The correct way to repair is to remove the engine and clutch housing. This will allow you to get at everything. If the bolts are broken off, they may just come right out easily. If not then traditional methods of broken bolt removal may be needed. Such as welding a nut to the bolt to provide a head for removal. Heating and quenching if necessary. Look at the bolt holes carefully they have a tendency to crack radially. If the holes are stripped they can be Heli-Coiled. If they are too far oversize already then a thread insert may be needed. Check the frame rails for cracks. Not only in that area, but also where the front crossbar bolts to them. This is another problem area. Check the bolts that hold the frame rails to the steering clutch housings for tightness, as well as the area where the frame is welded to the heavy plate. The rails have a tendency to crack there as well. Check all of the transmission to reverser bolts, and reverser to clutch housing bolts for tightness. These are all very common problems with the 450's. We have repaired many of them in this condition. Good Luck. Steve.

RANDY Fay · Post by **RANDY Fay** » Fri Mar 21, 2008 7:23 am

This was a real problem with the 450B--be sure to check side frame under bottom flange just below where these bolt are loose or broken--if it's broken out there or in the back where it bolts to final drive housing it should be replaced--If bolts are broken they can be drilled out these are very hard bolts and it will take good drill bits. I use left twist drills to avoid the problem of running the broken end of bolt into bellhousing--this will sometimes cause a problem of another kind--Heliciol i never had it hold not saying that it won't most of the machines I work on have to make a living and get misused If the bolts are just striped out i have drilled and tapped them to 7/8 and even 1" although all the spacers frame blocks frame has to be drilled also--- oversize bolts should be 8 grade--orignal size bolts should be a bolt kit from deere be sure to check bellhousing very close have fun Randy

Digger · Post by **Digger** » Fri Mar 21, 2008 9:25 am

Thanks for the replys Randy and Steve. I just bought the machine and when I found this site started to relize that I had to look alittle closer at what I bought. I was told that it was in pretty good shape. Oh well, buyer beware. Anyway looks like I have some work to do before I dare use it. Hope this helps other guys when considering a used jd 450. Will update progress. Won't start until weather warms up and the snow bank disappears. Maybe late April or May. Digger

jdemaris · Post by **jdemaris** » Fri Mar 21, 2008 2:23 pm

Digger wrote:Thanks for the replys Randy and Steve. I just bought the machine and when I found this site started to relize that I had to look alittle closer at what I bought. I was told that it was in pretty good shape. Oh well, buyer beware. Anyway looks like I have some work to do before I dare use it. Hope this helps other guys when considering a used jd 450. Will update progress. Won't start until weather warms up and the snow bank disappears. Maybe late April or May. Digger

You have to expect that from any crawler - but especially a Deere that has no transverse suspension of any kind - like many Cat, AC, and Cletrac crawlers do.

I just had a chance to buy a good running, good steering, and good looking 350 diesel dozer with a 6 way blade for $5000. But, after eyeballing it real close - I found just about every bolt to the steering clutch housings, reverser case, transmission case, track frames, side frames, etc. broken, loose, and/or stripped. I passed on it - I know what could be involved trying to fix it right.

From what I've seen after working on them since the 1960s - they generallly get hammered all over. The 350s worse than the 450s, but both have similar issues. If you found broken bolts in one spot - it's going to be related to other issues - i.e. & e.g. more broken, stripped, and/or loose bolts. This leads to cracked side-frames as well. The crawler is designed as a unit - and everything is supposed to be tight - in a way similar to building a bridge out of toothpicks. One weak link tends to screw up the rest.

In regard to Heli-coils - they never worked for us if drilled and installed by hand. The issue is - it's just about impossible to drill a tight, straight, accurate hole at a size of 3/4", 7/8", 1" etc. when done by hand. As a consequence, the Heli-coils don't fit as tight or true as they should. Besides that - it's not too hard to break a rib running a 1/2" or 3/4" drill with a bit that big. We had one guy the broke a few ribs - twice -when he got pinned behind a 3/4" drill attached to a long bar to keep it from twisting. John Deere had several remedies - a slip-clutch driven drill attachment and also an air-impact drill attachment.

Solid thread inserts work better - especially those that have locks. But, if there's enough metal left, drilling and tapping oversize will work.

digitup2 · Post by **digitup2** » Fri Mar 21, 2008 5:36 pm

Ok this is the contractors version of how to .I have had several 450B and 450Cs do this to me the easiest way to fix this is to get some reverse drill bits of the size to the tap you are going to use to take out the thread Also get a piece of rod the same size of the bolt shaft and drill a hole down the center line of the shaft sized to the reverse bits used to get as close to center of bolt thread when drilling .If the bolts have recently broke they will be lose still from the shakeing that broke them .I have broken two 450Bs and a 450C[It is not something you want to do ]but it is easy enough to do just take a three foot drop off an edge and come down onto a solid stop with only the right track and it will pop both bell housing bolts on the right side like zip .Replace these bolts with grade 8 bolts only and use some locktight on the threads .I kept a 3/4 in drive socket an extra long extention and swivle bar with the dozer for a while and kept things tight . The frame back plates usualy crack at the weld .Get some one that knows how to weld uphill for this job it is not a big weld job but it takes some skill to do right remember that 3/4 of those old Deeres have a crack in the frame some where [It may not be a virgin but heck it's in good company ].Digitup.

Digger · Post by **Digger** » Sat Mar 22, 2008 9:24 am

I really appreciate all of the replies. Another question, if I fine the side frame cracked other than along the weld where it attaches to the final drive, is it repairable by welding or is it like a bridge I beam where any welding along the web weakens it?

Digger · Post by **Digger** » Sat Mar 22, 2008 9:25 am

I really appreciate all of the replies. Another question, if I fine the side frame cracked other than along the weld where it attaches to the final drive, is it repairable by welding or is it like a bridge I beam where any welding along the web weakens it? Digger

Digger · Post by **Digger** » Sat Mar 22, 2008 9:26 am

I really appreciate all of the replies. Another question, if I fine the side frame cracked other than along the weld where it attaches to the final drive, is it repairable by welding or is it like a bridge I beam where any welding along the web weakens it? Digger

Digger · Post by **Digger** » Sat Mar 22, 2008 9:48 am

Sorry about the multiple posting, every time I previewed it gave me a error code.

pdmech08 · Post by **pdmech08** » Sat Mar 22, 2008 2:10 pm

Digger: Any vertical welds should be avoided if possible. If you need frame rails, they are available on the aftermarket and quite inexpensive. Check with Lavoy (board moderator) he may have them available, if not he can probably refer you to someone who does. Steve

Digger · Post by **Digger** » Sat Mar 22, 2008 2:51 pm

Great, thanks Steve, I'll check with Lavoy if I need them. Digger

Digger · Post by **Digger** » Sun May 11, 2008 10:32 am

Well, engine out, right side frame good, no broken bell housing case, transmission case o.k. Three of the right side frame bolts to final drive housing missing and the fourth loose. The question today, is it possible to use a 1 inch reemer from inside the bell housing and install the threaded locking inserts without taking out the bell housing? The threaded inserts I got are @ 1 inch long, is that long enough? Thanks for the help

Mulerider · Post by **Mulerider** » Tue Jun 10, 2008 9:45 pm

Our recently acquired (Aug 06) 450B/C also suffers from the stripped right side bellhousing bolts. The seller proudly told us of "all the new bolts", but the dim bulb in my head didn't come on to question why.
After several hours of use, the right side bolts were working their way out...
So I concocted a "hold down assembly", which is a welded/bolted unit to keep the bolts from backing out..

Side frames both have the reinforcements installed, and the unit runs/steers well. Motor is great (turbo unit). See my post in FAQ's as to what this unit really is (turbo B?).

I co-own this 450 with my neighbor; our wives may mutiny if we spend even MORE $$ (already spent big bucks on brake band/clutch discs) to get the bellhousing repaired...

I enjoy reading and learning from this site!

Greg

Digger · Post by **Digger** » Wed Jun 11, 2008 6:42 am

Update on clutch housing bolts. After an enormas amount of help from pdmech08, I had a machine shop install locking threaded inserts on both sides of the clutch housing with 277 loctite. In addition I also found a small crack in the right side frame, it had just started to round the corner and migrate up. welded that up. Also found crack starting at side frame where it bolts up to the steering clutch housing. Also welded that. throughly cleaned transmission case, no cracks, amazing!! More investigation revielded the need for new transmission pump and to resurface the mating front surface of the transmission cover. Also replaced hydrulic pump for dozer blade. Got a couple of hours of rain free weather yesterday and started to put everything together. Looks like rain the next three days (northern Wisconsin). Anyway, if you have any loose bolts on any dozer, tighten them right away, IT ONLY GETS WORSE. I happen to buy this money pit this way, and in a sick way I'm kinda of enjoying the project.

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