'90 FG434 Exhaust size, and other questions

[Berkshire90FG]

Hello all,

I've just bought a 71k mile 1990 FG434 and need to drive it ~700 miles home.

First, it needs a muffler and i want to bring one with me when i go to pick it up.
Can anyone tell me the diameter of the factory piping? I did not have any means of measuring it when i saw it.

Second, does anyone have a PDF of the owners manual?
I need to know if the rear rims are interchangeable with the fronts?

Third, I am aware that parts for these things are scarce but its even harder to find them without part numbers. Is there a parts breakdown available anywhere?

thanks for any help.

 

[SkiFreak]

The standard size of the exhaust is 2 1/4", but driving it without a muffler will not increase the noise level all that much.

The standard rims will fit on both the back and front.
Just remember that there are left and right handed nuts for the rims. LH on the left and RH on the right. The rear also uses bud nuts for the inside rims (square drive).

I have never found a parts manual for my truck, but I know that they do exist. I have always had to supply the VIN to the dealer in order you get required parts.
Look on sites like eBay for a workshop manual. I am sure you will find one there. If not... Google is your friend.

 

[Berkshire90FG]

Thanks!

I drove it and its much louder than I care to hear for 12-15 hrs haha. Ill get a 2 1/2" muffler and some reducer sleeves just to be sure it will work.

I did buy a torque multiplier that came with the bud socket.
I got the service manual for it, will just have to keep my eye out for a parts manual.

 

[11overlandram]

I have the same truck love it. Call Bruckners if ya need parts they can get most anything and ship it to ya. Did you check your frame for rust? Those that were used for plowing often are a kin to Swiss cheese.

 

[kerry]

Tom's Truck in California is a good online source for parts. You can call them. When I've needed parts I've given my vin and they typically had emailed me a parts diagram with part numbers and asked me which parts I needed. At least this was the case when I needed parking brake parts. There are shop manuals around in digital versions but you might have to dig really deep to find one for a 1990.

 

[11overlandram]

Tom's Truck in California is a good online source for parts. You can call them. When I've needed parts I've given my vin and they typically had emailed me a parts diagram with part numbers and asked me which parts I needed. At least this was the case when I needed parking brake parts. There are shop manuals around in digital versions but you might have to dig really deep to find one for a 1990.

Tom’s truck is good however I find them to have a large markup on most parts that I have asked for.

 

[kerry]

Tom’s truck is good however I find them to have a large markup on most parts that I have asked for.

More so than a dealer?

 

[11overlandram]

More so than a dealer?

Well my experience has been between them and Bruckners. Usually they are $50 to $100 more per part.

 

[Berkshire90FG]

I have the same truck love it. Call Bruckners if ya need parts they can get most anything and ship it to ya. Did you check your frame for rust? Those that were used for plowing often are a kin to Swiss cheese.

Swiss Cheese frame indeed. I got the truck home in one piece though, 13 hrs at 65mph & 3500rpm, probably the biggest workout that rig has ever seen. And it definitely lost some weight in rust scale haha. The dump body rails sit on very heavy gauge angle iron bolted along the rear rails. The rust jacking that occurred between them and the frame is mind blowing. It put 1/2" to 1" dents in the frame and in some areas broke holes in the frame. I have already removed the body and had custom heavy stainless steel rails bent for the rear, and ordered the pieces to TIG up a complete stainless exhaust, just waiting for those to be delivered.

What is interesting, nearly everything else is in pretty good contition. The axle housings, springs, etc. are in great shape. The frame behind the S bends is just dust. And the lugs are all frozen on. Snapped two front studs. Got the rear outer nuts off, broke the square off two of the budds and cursed my life choises leading to that moment... ah the joys.

As for parts, I bought the Mitsu parts software, Linkone EPC which at least gives me part numbers and diagrams to facilitate the finding and ordering of parts. It wasn't cheap at $129 and you have to install virtual machine software to run it, but I have already found NOS and used parts on ebay that will save me that much.Discouraging how many are discontinued though 😬

 

[SkiFreak]

Am I correct that you are planning on replacing the OEM frame rails with stainless ones, or did I read your post incorrectly?

 

[Berkshire90FG]

Am I correct that you are planning on replacing the OEM frame rails with stainless ones, or did I read your post incorrectly?

That is correct. Since the rear sections of rail behind the S curve in the frame are straight pieces, they can easily be replaced with stainless channel. I had a sheet of 1/4" 304 stainless cut and bent to fit inside the factory "S" stampings. The factory rails are 3/16" and garbage metal- now rusted to less that 1/16 or 3/32 in many places- so 1/4" t304 will be more than sufficient in terms of strength and flexibility.

 

[SkiFreak]

Yes, the OEM chassis on the FG is definitely not what I would consider "strong", far from it in fact.
My only concern with using stainless would be possibility of fatigue cracking, as stainless work hardens over time.