90 (four door) ex hub replacement / interchange

[Wes V]

I've got 1990 four door EX front spindles, hubs, and brakes on my hatchback and think one of the hubs may not be "true" and I want to replace it. It ends up that the factory no longer sells them!! The part number does not cross-reference to any other Honda (Acura) hub! So; Does anybody know if there are any other hubs that fit, but may have a different part number?? Wes V

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[QuarterMileMaster]

bump, I need to know this too

[CRX Toad]

Wes, you don't know? Man I am shocked I thought you knew all. I learn from your website.

I wonder if Tyson or Targa knows. I know that I read something about swapping hubs over in the RR/AX forum. I'll see if I can dig it up.

http://www.honda-tech.com/zerothread?id=824838

http://www.honda-tech.com/zerothread?id=992212

http://www.honda-tech.com/zerothread?id=913543

http://www.honda-tech.com/zerothread?id=1263038

[Tyson]

wes, i thought you went thru this all before. i would have told other ppl to go to YOU for answers....

actually i dont know the answer myself. ive sold several sets, never actually used them.

i know ryan (rywire) will know. he's done 5 lug conversions for customers. that requires hub swapping, so he might be familiar with whats already on there and is compatible.

[CRX Toad]

Dang Tyson you don't know either....what is HT coming to Wes, you and myself and we don't know. I hope the space time continum doesn't screw up.

[steronz]

i just got new bearings and had my Si hubs pressed in... didn't even think to check the part numbers. now i'm worried... so far everything fits, but I don't have the brakes on yet.

edit - i just need to pick up some DA caliper brackets, which i have planned for tomorrow, and i'll be able to mock everything up and tell you how successful the Si hubs are.

[CRX Toad]

Originally Posted by steronz

i just got new bearings and had my Si hubs pressed in... didn't even think to check the part numbers. now i'm worried... so far everything fits, but I don't have the brakes on yet.

edit - i just need to pick up some DA caliper brackets, which i have planned for tomorrow, and i'll be able to mock everything up and tell you how successful the Si hubs are.

That is cool. However this has nothing to do with the subject Wes has posted.

[jlicrx]

part number 03 in picture

https://www.hondapartsdeals.co...B++27

[steronz]

Originally Posted by CRX Toad

That is cool. However this has nothing to do with the subject Wes has posted.

maybe i'm confused then. I've got EX knuckles with Si hubs. Everything works. Isn't that exactly what he's asking for?

pictures on request... got everything put on today. the setup is:

EX knuckles, bearings, DA/EX rotors, caliper brackets, and calipers. Si/DX hubs.

[Targa250R]

Wes, did you have your Honda parts dealer do a locate on the EX hubs? They are sure there are none left in the country?

For reference, the EX knuckles use the same small wheel bearing as the Si/DX/LX knuckles, and not the larger Integra wheel bearing - which is why the bearings and hubs don't have an SK7 part number. However, I'm not sure why they aren't listed as the SH1 (Si/DX/LX) parts.

Have you tried physically comparing the SH4 (EX) hubs with the SH1 hubs? Are there any dimensional differences that would pose a problem?

Additionally, does anyone know if the EX knuckles could be bored out to accept DA wheel bearings and hubs? I don't have any EX knuckles in stock to check, so I don't know if this would be possible.

[Wes V]

jlicrx; Thanks for the link to the diagram, but I've already got it.

Targa250R; I'm real good friends with the local Honda Parts manager and he did a complete search for them.

As for comparing one against another, it's difficult due to the fact that the car is all together and I can't take dimensions off of the existing hub.

I also don't know if the inside diameter of the SI bearing (same as EX) is larger or smaller than the DA one. If the DA bearing has a larger inside diameter, then it may be possible to take a DA hub and turn it down to fit the SI bearing. I know this sort of thing is done when converting to 5 lug.

Thanks for everybody's input.

[CRX Toad]

I assumed you were talking about all Si kunckles and hubs. Sorry for the confusion.

Wes or anyone when the answer to this is actually found please post the follow up info up so that we know. I say this in regards to the 5 sets of EX knuckles on cars that I will/have worked on for myself and friends.

[steronz]

i figured the context of the thread would make things clear, but i should have specified. no harm.

so here's the picture i took this afternoon... nearest i can tell, whatever differences there are between the Si/DX/LX hub and the EX hub, it doesn't affect the operation of anything. everything bolted up just fine, the rotor turns freely, etc. i'd be interested if someone found out why they're different part numbers, but i declare the two to be interchangeable.



^^ EX knuckles, Si hubs

[dr_latino999]

So is the official conclusion for now is that the DX / LX (44600-SH1-A00) hub is a suitable replacement for the EX wheel hub (44600-SH4-A50)?

FIXED


Modified by dr_latino999 at 1:35 PM 1/13/2007

[Targa250R]

Originally Posted by dr_latino999

So is the official conclusion for now is that the DX / LX (44600-SH1-A00) bearing is a suitable replacement for the EX wheel bearing (44600-SH4-A50)?

The bearings are the same (44300-SB2-9xx). You're talking about the hub.

I really don't see any problem in using the SH1 hub; it seems to install fine, and any dimensional difference would have to be in the diameter of the brake rotor backing plate (that the wheel studs are pressed through). Since the wheel studs and rotor screws locate the rotor - and rotors are also hubcentric so they sit on the lip in the center of the hub if you don't use rotor screws - I don't think it would pose a problem if it was different.

I'd go ahead and order SH1 hubs. Make sure to take pictures or measure dimensions when pulling the old SH4 hubs off and compare them to the new SH1s, so we can settle this discussion.

[dr_latino999]

Oh ya, I think I meant hub but was looking at the bearing on the parts diagram, time to re-edit

[dr_latino999]

Bringing this back up as I'm now replacing the hubs on both sets of EX Knuckles I have. I have contacted a local Honda Dealer about having a new SI hub delivered to the dealer so I can see for myself where the difference is in the part numbers. I see that steronz used this setup successfully, but I'm hesitant to jump right in and purchase 4 SI hubs and have the offset or some other minute factor changed. Call me worrisome

Wes, what did you end up using in the end?

[CRX Toad]

There are some hardened race ones on the market too. I think OPM makes them. So you are going to replace the hubs int he EX spindles/knuckles? I am interested to know if this will work. Make sure you let us know the results.

[dr_latino999]

Originally Posted by CRX Toad

. So you are going to replace the hubs int he EX spindles/knuckles? I am interested to know if this will work. Make sure you let us know the results.

Yup, I figured why deal with ripping the bearing race off a 17 year hub when I just can pick up new ones for a decent price (127); also 2 off the 4 hubs are marred so reusing them is out of the question. Received word back from the dealer - Call Honda of America; called Honda of America - no part update hidden in the depths of their files. The best part is that when I brought up informing them if the SI hub was a 100% replacement so the part numbers could be updated, I was told that it would be easier to post it on "Honda-Tech then wait for the paperwork on a TSB."

I have purchased a SI hub, hopefully I'll have it at the end of next week for pictures.

[Wes V]

I still haven't done anything in regards to my EX hubs and really can't wait to see what dr_latino999 comes up with.

Possible things that could be different would be the "offset" of the surface that the rotor bolts too. A difference would cause the rotor to sit further outward (or inward).

Another possible difference would be the center indexing section. In other words, does this match the ID that is present on the DA (or EX) rotor.

Things we can rule out; the bearing surface is the same (Si same as EX) due to using the same bearing. The lug spacing is the same (4X100).

I'd REALLY like to feel comfortable about ordering a set of SI hubs.

Who is "OMP" and do they have a cross-reference that can be used? Do they list an "EX" hub?

It's nice that steronz was able to bolt up everything (really gives me hope). However due to the fact that the caliper is a floating design, it would offset to match the rotor placement (not necessarily a bad thing). Also, in his photo, it doesn't look like the center indexing section is smaller than the hole in the DA rotor.

I REALLY approciate everybody's help!

Wes V

[dr_latino999]

I come bearing gifts, information, and part numbers

<FONT SIZE="2">SI Hub vs EX Hub Top View</FONT>


<FONT SIZE="2">SI Hub vs EX Hub Side View</FONT>


<FONT SIZE="2">EX Hub inside 10.3" Rotor</FONT>


<FONT SIZE="2">SI Hub inside 10.3" Rotor</FONT>



The only difference that I can find between the two hubs is that the face is smaller on the SI hub. I am now confident to say that the SI hub (44600-SH1-A00) is a suitable replacement for the EX hub.

[CRX Toad]

Wes,

OPM has hardened hubs available since the OEM ones are prone to letting loose in racing conditions. http://www.opmautosports.com/index.html

Hummm so the Si is a tad smaller. There is hope for good replacement.

[dr_latino999]

Originally Posted by CRX Toad

Hummm so the Si is a tad smaller. There is hope for good replacement.

Originally Posted by Driven

The weight difference is as follows:
CRX Si (as shown) - 1.25lbs
GSR (as shown) - 2.5lbs

obviously, i have longer wheel studs on the GSR, but there's definitely more material on the hub.

The larger hub is going to help keep the brakes cooler by not transferring as much heat from the driveline to the brake rotor...

Bottom Line
the CRX hubs are CHEAPER than GSR and easier to find. if you have GSR knuckles/brakes and want to use CRX hubs, i don't see any reason why you couldn't.

CRX Hubs seem to be quite the interchangeable replacement part it seems.

[Wes V]

The only question I've got at this point is if both hubs have the same diameter raised section, where the hole in the rotor fits, is the same.

The smaller diameter on the SI provides less support for the studs (less material around the stud), but by no means is this a step backwards from what came originally on the car. In other words, the EX hub would be better if it was possible to buy them.

So, now I've got to find out how I can order beer over the internet.

Wes

[CRX Toad]

Wes while you are shopping for head lights in Italy see if they have the hubs. Maybe they can ship you some vino.

This has been added to the FAQ so please make sure the pictures don't turn into red boxes.