‘71 340 Duster Front Drum to Disk with Factory 14” Rallye Wheels - Problems

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JimG

JimG

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I have a 1971 340 Duster with factory 14” 5x4 BP Rallye wheels and factory manual drum brakes on the front. I have installed a complete 10.95" Front Disc Brake Kit (Stage 1) from DoctorDiff. This kit is supposed to fit with factory 14” Rallye wheels. The installation is correct per instructions and conversation with Cass at DoctorDiff. The car will not move freely, and the steering column shakes when attempting to move only a few feet. It appears that the calipers and/or pad retaining clips are contacting the inside of the wheels. I will put it back on the lift and verify contact. Any thoughts or input would be appreciated. Thanks!
 
JimG said:
I have a 1971 340 Duster with factory 14” 5x4 BP Rallye wheels and factory manual drum brakes on the front. I have installed a complete 10.95" Front Disc Brake Kit (Stage 1) from DoctorDiff. This kit is supposed to fit with factory 14” Rallye wheels. The installation is correct per instructions and conversation with Cass at DoctorDiff. The car will not move freely, and the steering column shakes when attempting to move only a few feet. It appears that the calipers and/or pad retaining clips are contacting the inside of the wheels. I will put it back on the lift and verify contact. Any thoughts or input would be appreciated. Thanks!
Click to expand...

Pics Bro, pics....
 
Professor Fate said:
If the calipers are making contact with the wheels, try a pair of these:
Set of 4 | 3mm Hubcentric Wheel Spacers | 5x100 w/ 57.1mm Hub bore | Flat | eBay
Generally not a fan of wheel spacers, but at only 1/8" thick it's more of a shim than a spacer- you won't need longer studs, and should be plenty to gain the necessary clearance without having a major effect on clearances elsewhere.
Click to expand...
Just to confirm what thickness will be sufficient, put washers on the wheel studs until the wheel spins freely, that is the thickness spacer you will need to order. DON'T drive it like this, it's just for sizing purposes!
 
Thank youn all for your relies! Much appreciated.

The calipers are absolutely making contact with the wheels. I removed the retaining clips and verified that it is just the caliper. There is less than a 1/16” max where it is not in contact with the wheel.

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Using your suggestion to test adequate clearance with flat washers as spacers, it requires 3/8” of washers on each stud to completely clear the caliper. I am simply not comfortable with that thick of a wheel spacer. This kit is advertised to fit!

IMG_3229.jpeg


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I would grind the caliper to fit, it won't reduce the strength of the caliper by much if any.
The suggestion to use spacers would work too, even though it's not ideal.
I would tend to grind the caliper to fit, because the wheel is hub centric, and spacing them out is not the best idea...
 
JimG said:
Using your suggestion to test adequate clearance with flat washers as spacers, it requires 3/8” of washers on each stud to completely clear the caliper. I am simply not comfortable with that thick of a wheel spacer. This kit is advertised to fit!

View attachment 1716191134

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Have you tried loosening the caliper bracket bolts to see if they'll slide inward any?

As far as "they're supposed to fit" goes, it's called tolerance stack. A little extra on that set of calipers, maybe a smidge on the caliper brackets, maybe those wheels were a bit smaller than advertised. It happens. I'm sure that combo is in fact just fine on other cars. That being said, the rallye wheels in particular have a history of not fitting with certain brake combinations.

I'd grind a little on the calipers and not worry about it. But a 3/8" hub centric spacer wouldn't hurt anything at all. Might require longer studs for proper engagement thread though.
 
I am assuming that going to a 15” wheel would also solve this problem completly. Would these wheels from Wheel Vintiques have adequate clearance?

15x6 Chrysler Rallye Silver Small | 5x4" bolt | 4" backspace​

 
JimG said:
Confirmed 4” backspace…..

View attachment 1716191140
Click to expand...

I just noticed this, but, you're not measuring that backspace correctly. Backspace is measured from the outside lip to the wheel mounting surface, not from the shoulder where the tire mounts. The backspace on those wheels is probably 4.25".

How wide are those rims? Are you sure they're factory? Because I don't think any of the factory 14" SBP rallye's would have 4" of backspace, let alone 4.25". The widest factory SBP rallye's would be 14x5.5, and they wouldn't have a 4" backspace.
JimG said:
I am assuming that going to a 15” wheel would also solve this problem completly. Would these wheels from Wheel Vintiques have adequate clearance?

15x6 Chrysler Rallye Silver Small | 5x4" bolt | 4" backspace​

Click to expand...

A 15" wheel should solve the issue based on where your contact is, yes.
 
Are you sure those are factory wheels, it looks like you have aftermarket rally wheels. I'm going by the welds and shape of the wheel center.

I've read several times hat aftermarket 14" SBP rallies will hit disc brakes and a factory rally wheel will clear.
 
Thanks for the information. Measuring to the outside lip is 4-1/8” exactly. I purchased the car from the original owner. The braodcast sheet came with the car. I could be wrong, but I believe the codes verify a rallye wheel option. At an outside chance, I guess the original wheels could have bee replaced with aftermarket wheels at some point.

The wheel stamping is 14x6.

Pics of original broadcast sheet and the wheel stamping below. Please comment.

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i'll throw another log on the fire: does that rotor look weird to anybody else? like the snout of it is way long? maybe there's a manufacturing defect and it was cast incorrectly and the face of the rotor is supposed to be 1/2" further out?

but a +1 to aftermarket wheels maybe playing a role, and another +1 to tolerance stack and giving the caliper brackets the ol' loosey-goosey and a shimmy shake before taking a soft wheel to them.
 
JimG said:
Thanks for the information. Measuring to the outside lip is 4-1/8” exactly. I purchased the car from the original owner. The braodcast sheet came with the car. I could be wrong, but I believe the codes verify a rallye wheel option. At an outside chance, I guess the original wheels could have bee replaced with aftermarket wheels at some point.

The wheel stamping is 14x6.

Pics of original broadcast sheet and the wheel stamping below. Please comment.

View attachment 1716191146

View attachment 1716191147

View attachment 1716191148

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View attachment 1716191150
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I'm not an original rallye wheel expert by any means, but my understanding is that 14x5.5" was the widest factory SBP rallye wheel. So 14x6" would be aftermarket.

I believe that the W21 on the broadcast sheet would mean that the car did originally come with rallye wheels, but of course that doesn't mean the rallye wheels on it are original.

It's a 50+ year old car, lots happens in that time even with an original owner. Parts get replaced.


junkyardhero said:
i'll throw another log on the fire: does that rotor look weird to anybody else? like the snout of it is way long? maybe there's a manufacturing defect and it was cast incorrectly and the face of the rotor is supposed to be 1/2" further out?

but a +1 to aftermarket wheels maybe playing a role, and another +1 to tolerance stack and giving the caliper brackets the ol' loosey-goosey and a shimmy shake before taking a soft wheel to them.
Click to expand...

Rotor looks pretty normal to me, the angle of the picture maybe making things look a little weird. The braking surface obviously lines up with the caliper, so, that part's not off. And the spindle dictates the location of the bearings, so, yeah. The snout looks long, but so does the rotor "hat" section unless you compare it to the caliper.
 
Thanks again for your patience, and the additional info. In reference to adjusting any play in the caliper brackets…..with the DoctorDiff kit there are no caliper brackets. The calipers mount directly to the spindle, and there is zero play. Pic attached.

IMG_3827.jpeg
 
the caliper bracket bolts to the spindle, it's the big C shaped piece that the calipers slide on-- the little retainer clips bolt into it.

www.doctordiff.com

Mopar 10.95" Disc Brake Slider Caliper Brackets

Reproduction 10.95" caliper brackets accept all commonly available '70s-'80s midsize Mopar (slider type) calipers, bearings and hoses.
www.doctordiff.com www.doctordiff.com
 
junkyardhero said:
the caliper bracket bolts to the spindle, it's the big C shaped piece that the calipers slide on-- the little retainer clips bolt into it.

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Click to expand...

Exactly. The bolts that go through the caliper bracket into the spindle can be loosened, and sometimes there’s a little bit of play there to adjust the bracket further in.

It’s not much at all, but in your case even a tiny fraction would help.

And BTW, the DoctorDiff stage 1 kit is just OE 73+ Mopar disks. All reproduction factory parts, he just has the rotors made up with the 5x4” bolt pattern. And the hub snout may be a little smaller in diameter than the OE BBP rotors, which may also be why it looks a little longer.
 
What did Dr. Diff say when you contacted him? He has parts made off shore (China) and sometimes the specs aren't exact. He quit offering the Eaton Tru Trac third members for this very reasosn.
 
BrianT said:
What did Dr. Diff say when you contacted him? He has parts made off shore (China) and sometimes the specs aren't exact. He quit offering the Eaton Tru Trac third members for this very reasosn.
Click to expand...

Definitely curious about this as well, Cass is usually very helpful about this sort of thing.

That said, those are aftermarket rallye wheels, not originals, and the aftermarket rallye wheels have a pretty established history of not clearing certain brakes.
 
I was in error on the caliper brackets. These were included in the kilt and used. I installed these months ago ands simply forgot.

Cass responded and said that these wheels are not factory, and that they have a different offset and taper. I am very surprised by this, but you guys are more knowledgeable than me, as this is my first Mopar after years of Chevy. That said, I trust they are indeed not factory.

I am now reluctently considering aftermarket 15x6, 4”BS, 5x4 BP wheels. My intention was to use the 14” Rallye’s. If I would have know that these wheels would not work with the kit and that I would need to go with 15”, I would have upgraded to a better option that Cass has available.

I do want to be clear about this….Cass has been an excellent source of information and great to deal with.

Here is his response:
Hi Jim,

With the exception of the rotor bolt pattern and register diameter, the brakes are reproductions of what '73-'76 A-bodies originally came with including cars optioned with 14" Rallye wheels.

If I remember correctly, I trial fit an OEM 5 x 4" bolt pattern Rallye wheel a couple years ago. Unfortunately, my order of 5 x 4" brake rotors is in transit and I don't have one in stock to confirm fitment.

Looks like you have aftermarket Rallye wheels, however. The inside profile of the rim is not the same as an OEM 5 x 4" bolt pattern Rallye. In addition, an OEM wheel also has 3 3/4" backspacing. What is the distance from the outside edge of the rim to the contact surface?

Cass
 
good news! you can swap out your rotors for 5X4.5" in that all of the rest of the components are the same. this gains a whole host of options in rims.

it still sucks that the repop rims won't clear the calipers, and you could always maybe grind a little off the caliper body and/or space the rim out a touch to maybe make it work.

so you at least have options
 
JimG said:
I was in error on the caliper brackets. These were included in the kilt and used. I installed these months ago ands simply forgot.

Cass responded and said that these wheels are not factory, and that they have a different offset and taper. I am very surprised by this, but you guys are more knowledgeable than me, as this is my first Mopar after years of Chevy. That said, I trust they are indeed not factory.

I am now reluctently considering aftermarket 15x6, 4”BS, 5x4 BP wheels. My intention was to use the 14” Rallye’s. If I would have know that these wheels would not work with the kit and that I would need to go with 15”, I would have upgraded to a better option that Cass has available.

I do want to be clear about this….Cass has been an excellent source of information and great to deal with.

Here is his response:
Hi Jim,

With the exception of the rotor bolt pattern and register diameter, the brakes are reproductions of what '73-'76 A-bodies originally came with including cars optioned with 14" Rallye wheels.

If I remember correctly, I trial fit an OEM 5 x 4" bolt pattern Rallye wheel a couple years ago. Unfortunately, my order of 5 x 4" brake rotors is in transit and I don't have one in stock to confirm fitment.

Looks like you have aftermarket Rallye wheels, however. The inside profile of the rim is not the same as an OEM 5 x 4" bolt pattern Rallye. In addition, an OEM wheel also has 3 3/4" backspacing. What is the distance from the outside edge of the rim to the contact surface?

Cass
Click to expand...

Yeah, I have to say your wheels are definitely not factory. I'd say that @junkyardhero is right on, that "8 29 02" stamp is production date.

And the factory 14x5.5" rallye's having a backspace of 3 3/4" vs the 4-1/8" your wheels have would probably mean the factory wheels would clear those brakes.

Definitely a bummer you went with the stage 1 brakes thinking it would let you keep the wheels you've got, totally understand that. And I get upgrading the brakes further if you knew you needed to get new wheels anyway! Makes perfect sense.

Have you asked Cass if he might exchange some of the brake parts you have toward the other brakes you wanted if you're buying new wheels? Because if you're talking about going to the Stage 2 brakes, only the rotors and caliper brackets are different, and those aren't used yet. Obviously I don't know for sure but it might be worth asking.
 
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