1995 Pathfinder rusting rear axle

[Lunartic]

Thanks to all who replied to my last post!!! Well here it is... My beautiful little 95 Pathfinder has got a bad case of cancer underneath in places. I live in northern Ontario where they dump all kinds of salt on the roads and this is the end result. After years of spraying it underneath it has come to this. Dooes anyone have any advice or ideas on how to repair this, as my pathy has 330000k on it and it's solid throughout everywhere else on the truck except this area. I saw another at the wreckers last weekend with the same problem, except buddys axle came right off on both sides of his truck and crashed. So needless to say I do not want that to happen to me. So any replies with this matter would be much appreciated...

Thanks

Blair...

Edited June 12, 2006 by Lunartic

[88pathoffroad]

You need to get under there and scrape off rust, poke around and find out if it's surface rust or if it's structurally degrading your frame first...then I think the only resolution is to clean the affected areas, cut out the rusted-through areas and weld new steel in, in pieces to match the original as closely as possible. Lots of people have done this to repair frame rust and rot.

[Precise1]

Yep, follow 88's advice. Brush, scrape then hammer problem spots to determine the extent of the rusting. Here are a few threads I dug up for you.

http://www.nissanpathfinders.net/forum/index.php?showtopic=5467&hl=rust

http://www.nissanpathfinders.net/forum/index.php?showtopic=5496&hl=rust

http://www.nissanpathfinders.net/forum/index.php?showtopic=5485

 

I know of someone who swears by denatured fish oil as a protector; it can be brushed or sprayed on, making it perfect for inside the frame...

 

B

[mws]

Yup, time to clean, scrape and investigate.

 

And get cozy with someone with a mig welder! Plate that sucker up and coat it thoroughly with POR-15 when done! 330K is just breaking in mileage...

 

And if you have ever considered putting in longer control arms...

[Trainman]

Here is another Canadian Pathy with the same types of issues: Nissan Truck Club link

 

Hope all this helps.

[KILLVOX]

A guy that i work with told me he uses this stuff and says it is great.

 

http://www.eastwoodco.com/jump.jsp?itemTyp...GORY&itemID=372

[Datsunman]

Here the roads are heavily salted during the winter so rust is inherent in most cars and as I own old Datsuns as a rule I've had more than my fair share of it. I have developed a few techniques to deal with it.

 

First and foremost is protection against it happening in the first place. I treat the underside of my cars with either a 50/50 mix of Waxolyl and underseal or some stuff called Astrolan (PX28) which is used by the military. Both PX28 and Waxolyl are similiar substances, a wax with rust inhibitors in it. Waxoyl is more "liquid" than PX28 but neither will ever dry out and go hard. PX is nicer because is is firm and dry to the touch once applied. I heat it until is extremely hot before applying as it's then very watery and will soak into seams and also into any rust that is present. I have coated the entire underside of my Terrano in it including the suspension and inside the chassis. On the underside alone I used two gallons of the stuff. I have also done inside the door bottoms, sills and inside the rear quarters around the wheel arches as well as up under the front wings behind the arch liners. Every enclosed space and area likely to rust has been coated in it. It's a really horrible, nasty job to do but well worth it in the long run. You could also use a similar substance made by Dinitrol or Tetrosyl.

 

I used PX the most as it's military spec and more robust than any other substance I've seen. I will use it in preference to paint as water seems to be unable to penetrate between it and the surface and it self heals to a degree when the coating is damaged as it always remains soft.

 

When it comes to repairing rust the golden rule is chop out all the rot! There's no point in welding plates over the rust as it will return very quickly. Cut back any damaged metal until you reach good solid steel. It's no harder to weld in a big piece than it is to weld in a small one so don't skimp on the cutting. I often use cardboard to make templates to help cut out replacement panels and sections. These can be made before the bad metal is removed. I also try to rebuild sections in the way they came from the factory, copying the original stucture, unless the original design is likely to cause future corrosion problems. Rust treat areas inside and out after repairs too.

 

I have yet to try any POR15 products as they are not widely available here, but a company called Frost supply it so I will be trying it on the old Datsun pickup I am currently restoring.

 

-Ed

Edited June 21, 2006 by Datsunman

[Slick]

awesome write up datsunman!

[513yj]

por 15 is the sheet. all you do is check for holes and weak spots as 88pathoffroad said, and if there isn't any and you don't need to repair then nock off the chunks or rust a little wire brush and slam on the por. you dont want it clean all the way as it works by chemically bonding to rust so some surface rust helps just not big chunks. if you have to or have already ground or wire wheeled off so you have bare metal, then por sells some stuff called metal ready cause it don't stick well to bare clean metal. be careful with the metal ready as it works fast and will cause a white film if left on too long. here it the up of michigan we get the salt treatment hardcore in the winter and i use por religously around here. oh yeah rubber gloves are nice, still got por on my hands from derusting my path from 2 weeks ago. hope this will help.

[Datsunman]

One more thing I just though to add... tools for removing rust. My favoured tools are..

 

4.5" Angle grinder - this is for hardcore heavy rust only really as you can do a fair bit of damage with a grinder. Used a thick solid disc for heavy rust and flexible fibre sanding pads for lighter stuff and smoothing out welds etc. You can also use a wire cup brush with a grinder and they are pretty effective too.

 

Crud Thug - this is an air powered wire wheel made by Snap-On. It's very effective for removing sealer, old underseal and general crud but no much good for actual heavy rust apart from when the wheel is new. Great for cleaning up prior to welding.

 

Strip & Clean discs - these are like a kind of foam/fibre disc coated in a very abrasive material and are made by 3M. They are very effective at removing just about anything from steel including rust, paint and sealer but they won't damage the metal itself at all. They do wear quite fast and are not cheap but have to be one of the best piece3s of equipment out there. They are used in a power or air drill.

 

Wire wheels - most wire wheels loose the efficiency quite quickly as they wear but they are still useful tools for getting rid of rust. I don't tend to use the larger diameter wheels anymore but I still use small cup brushes for getting into corners etc.

 

Chemicals - there's dozens of assorted rust treatments out there but I tend to favour the ones that actually dissolve rust rather than convert it. the downside is they take a lot longer to do the job. I use brick cleaner for a DIY store to soak away rust on smaller items suck as bolts, brackets and small components. brick cleaner is hydrochloric acid and it will dissolve rust completely but be warned...leave the items in to long and they will disslove too!

 

-Ed