2001 V70XC working with exhaust

[Xheart]

Thanks to our Howard, I have a thread 2001 V70XC Final drive woes.

The work requires handling of exhaust pipe, lowering from the hangers, perhaps removing it all together.

I will raise it on 4 jack-stand. Is there anyone here with the exhaust removal and install that would get me started.

Many thanks.

[JRL]

Seriously
Just remove the hangers, unbolt everything and hopefully it will all just come out easily (if not rusted)

[n00bkiller944]

Yep Pretty easy. You might wreck the bolts like I did but it is ok you can just replace the bolts with some grade 8 stainless when you put it back in!

[dirtyd851]

Stainless bolts should work great but are more prone to galling and stripping so a little anti-seize is a good idea. Grade 8 is not stainless though, that grade refers to high carbon steel which will rust but is stronger. Grade 8 is a strength specification, while "stainless" is an alloy type, of which there are many different specifications. Your standard stainless harware store bolt would be similar to a grade 5 bolt. Sorry, I'm a machinist, haha.

[n00bkiller944]

Stainless bolts should work great but are more prone to galling and stripping so a little anti-seize is a good idea. Grade 8 is not stainless though, that grade refers to high carbon steel which will rust but is stronger. Grade 8 is a strength specification, while "stainless" is an alloy type, of which there are many different specifications. Your standard stainless harware store bolt would be similar to a grade 5 bolt. Sorry, I'm a machinist, haha.

No thats good information to know! Thank you!

[Xheart]

Stainless bolts should work great but are more prone to galling and stripping so a little anti-seize is a good idea. Grade 8 is not stainless though, that grade refers to high carbon steel which will rust but is stronger. Grade 8 is a strength specification, while "stainless" is an alloy type, of which there are many different specifications. Your standard stainless harware store bolt would be similar to a grade 5 bolt. Sorry, I'm a machinist, haha.

Interesting that you say. Just the other day picking flange bolts M8 x 1.25 x 40 for rear shock mount, I asked the associate about the marker 8.8 on Zinc bolt and its equal stainless steel. He simply said stainless Steel would not rust.

Thanks for your input.

[Astro14]

8.8 is standard strength metric. About the same as grade 5 SAE.

For suspension, or other critical parts, you want a metric 10.9 grade which is high strength.

For the exhaust - pull the hangars off, you may get enough clearance. You can try to unbolt the system at the flange, but given the car's age there likely isn't a lot left of those bolts and you'll have to get out the die grinder...,

[dirtyd851]

Sorry we kinda highjacked/turned this into a bolt thread, ha! But here's a little more info that may help with the bolt designation...

The two-digit nomenclature is not used to describe individual steel grades and only applies to metric fasteners defined under ISO 965 (as well as derived standards)
The designation system is based on two numbers e.g 8.8 . The first number is the tensile strength of the bolt material (N/mm2 )/100. The second number is = 1/100.(the ratio of the Proof (or Yield ) stress and the Tensile strength expressed as a percentage = 100.[Yield (Proof stress) /Tensile strength] /100
meaning that a grade 8.8 bolt has a nominal ultimate tensile strength (UTS) of 800N/mm2 (or Mpa) and a nominal yield strength of 640N/mm2 (or Mpa).

I promise I won't talk about bolts anymore today!

[Xheart]

Sorry we kinda highjacked/turned this into a bolt thread, ha! But here's a little more info that may help with the bolt designation...

The two-digit nomenclature is not used to describe individual steel grades and only applies to metric fasteners defined under ISO 965 (as well as derived standards)
The designation system is based on two numbers e.g 8.8 . The first number is the tensile strength of the bolt material (N/mm2 )/100. The second number is = 1/100.(the ratio of the Proof (or Yield ) stress and the Tensile strength expressed as a percentage = 100.[Yield (Proof stress) /Tensile strength] /100
meaning that a grade 8.8 bolt has a nominal ultimate tensile strength (UTS) of 800N/mm2 (or Mpa) and a nominal yield strength of 640N/mm2 (or Mpa).

I promise I won't talk about bolts anymore today!

This would help someone somewhere. I have come across things not relevant at the time, but knowing it was there made the work possible. So thank you.

[Xheart]

8.8 is standard strength metric. About the same as grade 5 SAE.

For suspension, or other critical parts, you want a metric 10.9 grade which is high strength.

For the exhaust - pull the hangars off, you may get enough clearance. You can try to unbolt the system at the flange, but given the car's age there likely isn't a lot left of those bolts and you'll have to get out the die grinder...,

I would use new gasket and and bolts from Volvo parts when connecting it back at flange. It is not removed yet. But making sure I have evrything to complete the procedure.

Does the gasket need coating of sorts before placing?

[Astro14]

No coating on gasket. Any coating would just burn off anyway. Be prepared to cut old bolts out...

[Xheart]

No coating on gasket. Any coating would just burn off anyway. Be prepared to cut old bolts out...

Is dremel type 4500 rpm rotary tool with cutting disc do the job? Would you consider nut splitter?

[dirtyd851]

Those cutting disks work pretty decent on a dremel, they also sell thicker, larger diameter discs that are reinforced that dont shatter as easily and last longer than those thin ones that come in a plastic tube. Once you get a slot cut in the nut a chisel or flat blade screwdriver can be used to spread the nut apart as well if you cant get a good angle to actually cut the end of the bolt and nut off. I like using a Milwaukee cordless angle grinder for those jobs...that thing comes in handy for all sorts of odd jobs.

[Astro14]

Is dremel type 4500 rpm rotary tool with cutting disc do the job? Would you consider nut splitter?

The Drexel does a good job with the thicker, reinforced disks if you're patient.

I doubt there's enough nut left to split on an 11 year old bolt...it's probably a lump of corroded steel and not much else...

[Xheart]

For suspension, or other critical parts, you want a metric 10.9 grade which is high strength.



There is always a talk of broken rusted bolts, and stripped nuts. I now have 10.9 grade replacements. Thank You.

[Xheart]

The Drexel does a good job with the thicker, reinforced disks if you're patient.

I doubt there's enough nut left to split on an 11 year old bolt...it's probably a lump of corroded steel and not much else...

For some reason, I was imagining these were copper nut/bolt.

[Xheart]

I now have the replacement, bolts, nuts, and the gasket from Volvo. One side with black coat, the other aluminum like finish.
Is there a right way for the gasket to go on?

[Xheart]

Those cutting disks work pretty decent on a dremel, they also sell thicker, larger diameter discs that are reinforced that dont shatter as easily and last longer than those thin ones that come in a plastic tube. Once you get a slot cut in the nut a chisel or flat blade screwdriver can be used to spread the nut apart as well if you cant get a good angle to actually cut the end of the bolt and nut off. I like using a Milwaukee cordless angle grinder for those jobs...that thing comes in handy for all sorts of odd jobs.

Checking in to share my progress.
4722

The bolt head is cut-off.
I believe there is no thread on either connecting exhaust.
Could the stud now be pushed out while the nut is still on?
Is there a better and gentler way, may be pull it out?

[dirtyd851]

Yeah, you should be able to just tap the bolt through, I'd cut both heads off first though. That way you should be able to use a jiffy bar or a flat head screw driver between the flanges to help persuade the corroded bolts loose since it looks like you have kind of a confined space to tap the bolts out. Just be sure not to damage the flange surfaces too much.

[ssicarman]

If the piece that you cut off on the left side of the pipe in the picture never had a hex on it, looking at the other side they did not, then they are studs that are pressed into the pipe and splined to prevent turning. Use a hammer and punch to tap them out.

[Xheart]

I will cut-off the head of the other bolt/stud first. It takes an hour with the rotary tool and a minor neck pain.

I tried the punch with a 1lb hammer to asses the required force, it did not move, but the entire exhaust assembly started to shake a bit. Worried of damaging a seal upstream, and stopped.

Any thoughts? Would heating the flange with propane torch help it move out?

Bolt threads are totally rusted and worn. I will start the morning with removing the head of the other bolt first.

I have the calm and patience for this complicated projects of Final Drive oil leak fix, just need little nudge from you.

Many thanks.

[dirtyd851]

You can use a propane torch to try and heat up the flange...you want to try and get as much heat into the flange without heating up the bolts as much. You're trying to get the steel flange to heat up and expand. Obviously there will be heat transfer to the bolts but just thought I'd mention it so you don't aim for the bolts is all. It is probably hard to tap on the bolts with the exhaust being primarily rubber mounted. If you don't have a jiffy bar you may be able to tap a flat head screwdriver between the flanges and either tap it in like a wedge or twist the screwdriver head. If the screwdriver has a square shaft you can put an adjustable wrench on the shaft and turn it or try turning the screwdriver handle with a channel locks or similiar.

[Xheart]

1 1/2 inch cut off disk is all that would fit the space.
For the second one, I am working from the nut side. A small portion of the shank was cut off. Now slowly chipping away at the nut.
Exterior is all rusted, but inside is hard and shiny.
4726

[Jorge-789995]

Your standard stainless harware store bolt would be similar to a grade 5 bolt. Sorry, I'm a machinist, haha.

I think stainless is closer to a grade 2 bolt. I would not use stainless in place of a grade 5 bolt. For some reason, the stainless bolts from my hardware store have been junk compared to those purchased from places like McMaster Carr.

[Xheart]

Few drops of machine oil helps with cutting, but I have shattered several disk during the last session. Either nut is not off yet.
The passenger side space is narrower than the driver's. The rotary tool handle is bit wider, so I am adjusting as I go.

Starting my 4th day of removal, I have few thoughts for your comments:
1) would it be better to use a 3" stainless steel cutting disk, which will require more room for the tool, hence...
2) would unscrewing the two brackets, toward the rear and one holding muffler, angle and lower it enough to fit the 3" cut off tool?
3) would lowering put strain on CAT assembly sensors, gasket, and items near exhaust manifold?
4) or bend/crack any part of the component th

[Astro14]

Lowering will risk cracking downpipe flex joint (ask me how I know...).

If you're breaking discs, it's because there is a side load on them...or you're pressing too hard....let the tool do the work, don't apply pressure to the dremel....just let it cut...you can cut through a bank safe with a dremel...if you're patient....

[Xheart]

Lowering will risk cracking downpipe flex joint (ask me how I know...).

If you're breaking discs, it's because there is a side load on them...or you're pressing too hard....let the tool do the work, don't apply pressure to the dremel....just let it cut...you can cut through a bank safe with a dremel...if you're patient....

Thank you Astro.
The optimism had started to fade a bit.
Using oil more frequently, no loss of disc.
Fewer sparks today as compare to yesterday's fireworks.
I would like to believe fewer is better with study pressure.
One has to look real close to determine where the nut ends and the flange surface begins.
I may nick the flange before knowing.

[Xheart]

For a family man it takes 5 painful days.
After separating at the flange, loosen 17mm muffler bracket, and 12mm brackets bolts to lower 1" while supported with bungee cords.
Support the muffler with bottle-jack use wood piece for buffer.
Pull out the rubber hanger from the tailpipe.
Remove the bungee cords starting at flange.
Let the beast rest a bit before move it aside.

Many thanks.

47314732

[n00bkiller944]

Ever get it off? lol

[Xheart]

Ever get it off? lol

Yes. All stainless steel, but bulky and heavy.

[Xheart]

It is now two weeks since the exhaust was put back together.
While off, it allowed me to inspect the heat shield components from front to back. The heat shield needs bit more care when working with the last hangers at the tail, heat shield is attached to the bracket that holds the last hangers. Pulling at this hanger bracket is not recommended.

It is all safe and working well. The 8" long burnt oil around the exhaust pipe surface directly below the FD cover plate is now clean and restored back to stainless steel.

Reused all fasteners, but new seal and fasteners at the CAT.

Pictures would come over the weekend.