RCV 300M Rear Axle Cone Washer Issue

[ThreeEyedBandit]

If your studs were the original version, yours would not be proud - and would be ok. As the lower photo in NeverFinis's #31 post shows, the studs now supplied by Toyota for the rear have been changed to the studs used in the front, which are longer. He did not mention when that change occurred.

The ones I removed where the longer shoulder so must have been replaced at some point, as with the ARP that I installed. They both worked with the RCV and factory flanges.

All the studs I have on hand have the same shoulder length(longer) as shown in your drawing earlier, this is where the confusion is. Why do studs with the same shoulder length sit in drastically different depths?

You said that you where installing them finger tight, what happens if you double nut them, blue loctite and torque them in?

If it was me, I would machine a light press fit C/B into the hub, but I have a machine shop at my disposal. Non machine shop Matt would torque the stud in and stack some washers and run it without second thought.

 

[Gerrha]

The ones I removed where the longer shoulder so must have been replaced at some point, as with the ARP that I installed. They both worked with the RCV and factory flanges.

All the studs I have on hand have the same shoulder length(longer) as shown in your drawing earlier, this is where the confusion is. Why do studs with the same shoulder length sit in drastically different depths?

You said that you where installing them finger tight, what happens if you double nut them, blue loctite and torque them in?

If it was me, I would machine a light press fit C/B into the hub, but I have a machine shop at my disposal. Non machine shop Matt would torque the stud in and stack some washers and run it without second thought.

I guess there is still somewhat of a mystery here. I don't have a machine shop, but plenty are close. The thing is, I dread the thought of tearing down the axles again to get the hubs off for the C/B. I have ordered the high-profile flange nuts, which I do plan to take to a machine shop for a 3-mm depth C/B at 8-mm diameter. I am hopeful that will solve the problem.

 

[ThreeEyedBandit]

I guess there is still somewhat of a mystery here. I don't have a machine shop, but plenty are close. The thing is, I dread the thought of tearing down the axles again to get the hubs off for the C/B. I have ordered the high-profile flange nuts, which I do plan to take to a machine shop for a 3-mm depth C/B at 8-mm diameter. I am hopeful that will solve the problem.

Sounds like a solid plan. Also get some hardened M8 washers as a backup, if they are on hand then you won't need them

 

[PIP]

Counterboring extra tall nuts sounds like a straightforward solution.

 

[Broski]

IMO you need to run at least a couple of dowel pins to do that you need to pull the hubs back off.
Once you do that may as well run them all and have the studs counter bored.
In my mind it make no sense to run chrome Molly RCV axles and no pins.

 

[Gerrha]

IMO you need to run at least a couple of dowel pins to do that you need to pull the hubs back off.
Once you do that may as well run them all and have the studs counter bored.
In my mind it make no sense to run chrome Molly RCV axles and no pins.

Well, if it needs to be done... Has there been a consensus regarding the potential misalignment of the dowel pins? I read a lengthy previous post in which this was discussed back and forth with no real conclusion.

 

[PIP]

Well, if it needs to be done... Has there been a consensus regarding the potential misalignment of the dowel pins? I read a lengthy previous post in which this was discussed back and forth with no real conclusion.

Find a good machinist. This is very basic work for anyone worth a sh!t.

 

[Gerrha]

Find a good machinist. This is very basic work for anyone worth a sh!t.

Here is a follow-up for my original post. As PIP stated on April 7, find a good machinist. This is very basic work for anyone worth a sh!t. This turned out to be so true. I waited for my "machinist" to complete the job I requested from about April 15 until last week... Finally, the job is done, and it turned out fine. Photos are below.

For each rear axle hub, I had six RCV pins installed and now for the most important part, I had the six OEM stud holes counter-bored 1/4" deep, which solves the thread problem discussed throughout this post.

This same problem occurs on the front hubs as well, but instead of removing the front hubs and counter-boring them like the rears, I have chosen to counter-bore extra-deep flange nuts from McMaster-Carr. I will post a follow-up for the front when that is done.

 

[Broski]

Well All I can say is that mine don’t have that issue.
Still know why you hade to go through that.
Thanks for the update

 

[Gerrha]

Another follow-up here to show how the front hubs worked out. For the front, I chose not to counter-bore the hubs themselves, but instead counter-bore flange nuts purchased from McMaster-Carr. This was a lot easier and cheaper than the counter-bored rear hubs.

I counter-bored the 0.47" tall flange nuts 0.15" deep to give the necessary clearance for the studs. This left 0.32" of thread engagement compared to 0.26" in an OEM nut. The only issue I found is that the flange diameter was a little large and it protruded slightly above the outer diameter of the flange itself making it difficult to get the wheel mounted. This small problem was easily overcome by grinding off some of the flange OD using a bench grinder.

I have attached three photos showing the process.

 

[Broski]

I’m glad that you got it worked out.
Did you ever figure out what was wrong with the plan to thin bolt too long. The cones is too small?
Inquiring minds want to know

 

[Gerrha]

I would machine the counterbore in the hubs deeper, but I'm a machinist.

I'd say you'd have a good chance of success with a decent, slow rpm drill press that has a quill stop or that you can rig the quill travel to stop at your target depth.

I wouldn't attempt it with a hand drill.

If you brought these to me I'd set them in a cnc mill, sweep in the dowel pins for alignment and pick up on center, draw it up in CAM and helical bore the threads out and chamfer the start of the threads below the bore. I'd have to run the first one a few times to sneak up on the proper depth.

Probably an hour to do both hubs.

You might look for a good local machine shop and ask how much they'd charge to fix these for you.

It cost $500 and 2.5 months for both hubs...

 

[Gerrha]

I’m glad that you got it worked out.
Did you ever figure out what was wrong with the plan to thin bolt too long. The cones is too small?
Inquiring minds want to know

Never could find a reason for the initial issue. I suspect others have the same problem, but they do not see it and just keep going without a hitch.

 

[Marvelicious]

It cost $500 and 2.5 months for both hubs...

I don't think your machinist wants repeat business.

 

[Broski]

Never could find a reason for the initial issue. I suspect others have the same problem, but they do not see it and just keep going without a hitch.

I just had mine apart and looked and found no issue.
RCV axle and flange I snapped an RCV axle if those flange studs were lose I would have had a problem there first

I took a picture as you can see with out the washer and I still can’t see the shoulder.

 

[Gerrha]

I just had mine apart and looked and found no issue.
RCV axle and flange I snapped an RCV axle if those flange studs were lose I would have had a problem there first View attachment 4174421View attachment 4174419I took a picture as you can see with out the washer and I still can’t see the shoulder.

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I just had mine apart and looked and found no issue.
RCV axle and flange I snapped an RCV axle if those flange studs were lose I would have had a problem there first View attachment 4174421View attachment 4174419I took a picture as you can see with out the washer and I still can’t see the shoulder.

Yes, I just don't know what is really going on.

 

[PIP]

It cost $500 and 2.5 months for both hubs...

That is out of line.

$200 is a realistic amount for doing those hobs on a nice CNC mill in a 2 week timeframe.

 

[Gerrha]

That is out of line.

$200 is a realistic amount for doing those hobs on a nice CNC mill in a 2 week timeframe.

Yes, but too late for me now. I will not make a similar mistake again.

 

[NeverFinis]

FYI I paid $120 to have both hubs machined for the 6 RCV dowel pins @cruiseroutfit. Price as of 11/1/2024.

 

[Broski]

FYI I paid $120 to have both hubs machined for the 6 RCV dowel pins @cruiseroutfit. Price as of 11/1/2024.

View attachment 4176251

There no longer offering that service