Plasticman

Well, I am starting the conversion to front disc brakes on the 62. However, the install instructions leave me cold. I know what needs to be done, and how to do it, but would of thought better instruction should of been included (no bolt torque specs, minimal diagram, no wheel bearing adjustment specs., etc.). I won't mention the mfg. of this kit until I see the complete results.

One question (and it has been discussed previously, but thought I should raise it again - since we may see some new member's thoughts) is the proper wheel adjustment for these kits.

Most (if not all) of the currently available kits use Ford wheel bearings (S-2 and S-13) with GM rotors and calipers (73 or thereabouts Chevy Monte Carlo, etc.).

Now the original C1 spec with ball bearings can be tossed out, since we are dealing with Tapered Roller bearings now.

GM's specs for mid 70's disc brake wheel bearings flatly state that anything even close to finger tight will cause bearing failure, and the spec is .001 to .008" end play.

However, since these kits use Ford bearings, I am going to use the mid 70's Ford spec. This is:

1. Tighten to 17-25 ft.-lbs. while rotating the disc (to intially seat the bearings).
2. Back off the nut 1/2 turn.
3. Retighten the nut to 10-15 in.-lbs. (NOTE: That is INCH pounds, not ft.-lbs.)! Then lock it in place.
4. Note that Ford used a "finer" method of holding the nut in place (a multi-grooved castle "holding" nut that went over the spindle nut, and allowed for a "finer" adjustment than the GM method of one of the 2 cotter key holes), so the adjustment could be held tighter. If I find that I have to back off the nut too much (to align the cotter key to the hole), I will add a shim washer or 2 for a "better" adjustment.

The one benefit to using the tighter Ford spec is the less looseness of the wheel (in relationship to steering input). A C1 with stock suspension/steering can use all the help possible! It will also limit the amount of "knock-back" of the disc brake pads (ensuring a higher pedal hopefully).

Has anyone else who have used one of these kits (Master Power, ECI, Eklers, CC, etc.) seen a recommended wheel bearing adjustment spec.?

Let the comments begin!

Note: In order to use the Ford spec with these bearings, I am aware that I must use the Ford EP (with moly) recommended disc brake wheel bearing grease.

Plasticman

DZAUTO

NOPE!
My experience with disc conversion on the early cars is the Master Power Brakes front disc conversion (retained rear drums) WITHOUT any power boost and the MPB adjustable proportioning valve (installs on the right frame rail near the battery. The latest was on a customer's 57 about 1yr ago. Its still stopping just fine.
The MPB adapter sleeve which they supply goes on in place of the normal 53-62 inner bearing race. The ones I did were a REAL BEAR to get all the way on the spindle. I used a puller (and fabbed an adapter plate) on the first one. The second one, I removed the spindle from the spindle support and placed it in the press to get the adapter sleeve on. That method was much easier. While I was at it, the second car needed kingpins, so I also made an extra sale!

Plasticman

DZAUTO,

The kit I purchased "says" you can install the adapters by pounding them onto the spindle via a pipe and hammer! In looking at the fit and machining, I decided to chamfer the inside corners before I will try this, but I see potential problems already. Just the fit of the inner bearing to these adapters was very tight, with the bearings easily bound in a slightly cocked position. I chamfered these corners, and the bearing slips on easier, but still can **** and bind if not careful.

I looked at the Timken website this morning, and interesting that they only specify the GM spec. for wheel bearing settings (.001" to .007" end play).

See the Timken .pdf page here:
http://www.timken.com/industries/aut..._Issue%201.pdf

Thanks,
plasticman

kidvette

Plasticman,

Sounds like you have the SSBC kit. I used it with the same torque spec's you stated and the bearings run smooth.

Plasticman

Kidvette,

Sorry, but I stated 2 different specs. Was wondering which spec. that you used (the Ford "preload" spec., or the GM .001" -.008" endplay spec.).

The kit I purchased is not from SSBC (man, are their prices high!). Had a bad experience (poor product and customer relations - their exact words: "YOU USED IT, IT'S YOUR'S!") previously with SSBC on my 87 Vette, and will not go back to them.

Thanks,
plasticman

67L36Driver

No experience with disc conversion kits for C1's: BUT lots of experience with bearings in general including tapered roller bearings.

Go with the Timken specs but not as much endplay. .001" - .003" endplay would float my boat.

The preload and backoff routine is to insure the cups are seated solidly.

I always did like the F%$d setup with the tin castelated nut thingy.

kidvette

Plasticman,

I used the ford spec's and things feel fine.Even a little better than before the replacement.

Good luck
Kidvette

kenmo

I converted ny 60 over using the ECI kit... My kid brother a licensed mechanic assisted with the conversion and did the bearings for me... I'm trying to get hold of him to see if he remembers...

Cheers

Kenmo

71zman

Plasticman,
I have no answer to your problem but am curious what made you make the jump to disc brakes? As you well know being a long time forum member, there are those who argue that the stock drums are oversized enough so heating and brake fade should never be a problem with normal road driving. Clearly there are others who think the discs are the only way to go but, in my opinion, with no technical reasoning. I always respect your knowledge so what factors made you switch?? Also are you changing the master cylinder?

thanks

Plasticman

Thanks guys!

I just went to the SKF website, and found an interesting page for Tapered Roller Bearings that explains their thinking on preload.

Here is the link if your interested, but I copied their words directly (see below):

http://www.skf.com/portal/skf/home/p...newlink=1_0_83

They state for Tapered Roller Bearings:

Depending on the application it may be necessary to have either a positive or a negative operational clearance in the bearing arrangement. In the majority of applications, the operational clearance should be positive, i.e. when in operation, the bearing should have a residual clearance, however slight, see section "Bearing internal clearance".

However, there are many cases, e.g. machine tool spindle bearings, pinion bearings in automotive axle drives, bearing arrangements of small electric motors, or bearing arrangements for oscillating movement, where a negative operational clearance, i.e. a preload, is needed to enhance the stiffness of the bearing arrangement or to increase running accuracy. The application of a preload, e.g. by springs, is also recommended where bearings are to operate without load or under very light load and at high speeds. In these cases, the preload serves to provide a minimum load on the bearing and prevent bearing damage as a result of sliding movements of the rolling elements, see section "Requisite minimum load".


There is also another section that relates to heat in the assembly and how that affects preload. Example: If in operation the shaft becomes warmer than the housing, the preload which was adjusted (set) at ambient temperature during mounting will increase, the increase being greater for face-to-face than for back-to-back arrangements. In both cases the thermal expansion in the radial direction serves to reduce clearance or increase preload. This tendency is increased by the thermal expansion in the axial direction when the bearings are face-to-face, but is reduced for back-to-back arrangements. For back-to-back arrangements only, for a given distance between the bearings and when the coefficient of thermal expansion is the same for the bearings and associated components, the radial and axial thermal expansions will cancel each other out so that the preload will not change.

Note that automotive bearings are configured in the "back to back" arrangement.

Plasticman

Plasticman

71zman,

I thank you for the compliments!

While I agree that the drum brakes are sized correctly to bring the Vette to a fast stop, my concern is with control and repeatability, coupled with adjustment (or the lack of needing it). I find myself drivng the 62 more frequently now that I am in Florida, and frankly I thought Chicago area drivers were bad, but some of the "seniors" here in FL scare the crap out of me! For the most part, Chicago drivers drive fast, don't maintain proper vehicle spacing, but do have the skill to match. Florida drivers (again, for the most part) show better manners, maintain good vehicle spacing, and have skill honed from many years on the road. However, every once in a while, a bluehair will do something real dumb (right in front of you), and not even realize it.

I find that when I have to really get on the binders (couple of times recently), the 62 stops great, but does a jerk left, then a jerk right, and a then almost a straight stop (in the meantime I am trying to compensate for the jerks - both in the brakes and on the road). I went through the brakes a couple of years ago (replaced just about everything, did the major and several minor adjustments), and have tried to readjust the brakes recently (to straighten out the jerks). Having failed (and the suspension and steering are in great shape, so I cannot find a fault there), I have essentially "given up" and am willing to try the disc brakes. Note that a fellow 62 friend has the disc on all four wheels, and I like them - a lot!

As for changing anything else, no, I am going to try to piece meal it only as needed. I have seen the dual master cylinders, and don't know that they are worth the additonal "comfort level" of safety. Over the years I have had one brake failure where a dual master helped (rusted rear brake line on my 70 Vette), and the pedal still went to the floor, but a 2nd pump stopped the Vette. Most of the brake failures (where a dual system will save you) are really related to maintenance. If you have confidence that your system is in great shape, I don't see the need for the dual master. I also see that most C1's with the extended dual end up doing some minor surgery to make it fit. I am trying to make mods that will show no evidense, and can be returned to stock sometime later. I have been told that I "may" need to remove the residual pressure valve in the existing master. Some needed to remove it due to the front discs dragging, some did not (to be seen). Also, some saw the need to put a separate residual pressure valve in the rear brake lines to the rear drums (to prevent the rear cylinder lip seals from sucking in air on a fast pedal release). If I decide to convert to 4 wheel discs, then that would be a waste, but again - to be determined.

Bottom line is that disc brakes should offer better control (stop in a straight line), repeatability, and not need adjustment. All positive benefits over the drums. But also we will see what possible negatives show up!

Note that I also had purchased a set of the tapered roller bearings for the stock C1 hubs, but did not convert them. The new kit has these bearings (as part of the kit), and that is another plus. If the discs work, I will sell the C1 Taper Roller Bearing set.

Thanks again,
Plasticman

JohnFromVentura

Plasticman: I have a similar kit (Ford bearings, Chev rotors and push on inner race) on my 57. I set mine tight (but still turnable) and then backed it off to the first cotter pin location. If the thread is say 25 thds/inch (.040 per turn) and six locations for the cotter pin it yields about .006 per cotter pin location. This should put you in the range. I have over 12K miles on them and no problem. With a stock single master cylinder I can pull it down from 100 MPH without any problems. If you get into a C1 caravan make sure you're at the rear or the drum brake guys will run right through you!
John

Mike Swanson

I installed ECI's kit same way as johnfromventura discribed.
I cleaned up the faces of the spindle and the inner bearing adapter and seated them using a 1 1/4" piece of PVC conduit that I had laying around the shop. Worked perfectly.
I did add the dual master cylinder kit from Jim Meyers at the same time. Results are smooth straight stopping that blows me away everytime I come up to red light. I was thinking on adding rear disc brakes, but as it stands disc and drums work great for me. Also Jim Meyers adds a proportioning valve for the rear that I set up on wet roads one afternoon. Hope this helps.
Mike

DZAUTO

John,
It is true that the instructions say that you can drive the bearing adapter onto the spindle with a length of pipe and hammer. The first disc conversion that I did, I drove on the adapter on the first side and decided that was all of that!!!! For the other side, I used a puller and a plate that I fabricated. After that, I now pull off the spindle and put it in the press. That's how I will do them from now on.
After hammering on that first adapter, I gave consideration to how much impact was being absorbed by the other joints in the suspension, mainly the upper and lower outer shafts and especially the kingpin and bushings!!!!!!!!!!!! I DID NOT LIKE THAT!!

Plasticman

John,

Thanks for the advise! Most of our caravans are C4-5-6's, but have to be careful of a C1 sneaking up behind me.


Mike,

Thanks for the info. I can see why the proportioning valve is needed, but will await until I have a chance to test it with the single master cylinder (and go from there). May want to go full boogie with the 4 wheel discs (will compare mine to my buddies 62 with the 4 wheel discs - his stops very nicely with great control).

Tom,

I understand what you are saying about hammering on the suspension and kingpin bushings! I will check the interferance fit dimensions, and if over .003", it will need not only the press, but some extra machining. The adapters are not smoothly machined (except the outer seal surface which is pretty smooth), and I can see slight variations in measurements between the 2 adapters (so I have reasons for the extra time to measure and do it right).

I have made disc brake upgrades in the past (which also needed adapters), and really don't see the need for the the inner adapter to be a "hard" press fit. As long as it does not move around, it should be sufficient. I made the adapters on 2 other vehicles, and both are still on the road (one of them after 220K miles after the brake upgrade!).

Thanks guys!
Plasticman

kenmo

Spoke with my brother....the bearings were installed as per JohnFrom Ventura... I added a proportioning valve, as I using the Master Power Brakes dual mc... Installing the dual mc was one of the first things I did 20+ years ago... 2 yrs ago I did the disc brake conversion...

Plasticman

Ken,

Thanks for checking!

Plasticman

Mike Swanson

I'm not sure how much "hammering" is implied, but "seating" is not hammering. Thought I'd clear that up. It's all there in the instructions from ECI, their kit bolted on like it was factory parts!

JohnFromVentura

Clean the spindles up with Scotch Brite and deburr the sleeve. As someone noted I made an installing tool by cleaning up a short section of 1 1/4 pipe. I put lots of duct tape on the business end, put a 2X4 over the other end and hit it easily with the side of a 2# hand sledge. Both sides went right on!

Plasticman

Well, I started the install today. The interferance fit of the adapters was .0015" to .002"., and I made an aluminum plate (with a circle cut out of it) to go between the adater and the pipe, so I did not mar the adapter. I only finished one side (more on that later), and the one adapter went on with minimal force, yet is firm in place. So far so good!

However, when mounting the caliper plate, I noticed that 2 of the bolts are too long, and needed to be shorten (especially the forward upper one, since the extra length would of prevented a grease gun from going onto the zerk fitting for the king pin!). A trip to the band saw solved that.

Next was the caliper mounting, which also did not go smooth. These are rebuilt calipers, and the left differs from the right in casting configuration and markings, but both are the same size, etc. The upper hose boss (portion that locks the hose in position) on the right caliper interfered with the rear upper mounting plate bolt and nut. A trip to the sander solved that, and the other caliper should not have that issue.

Next was the flex hose. Again, this right caliper has a different configuration for the hose, and the hose fitting would not seat properly on the caliper. I ended up grinding on the hose "boss" to make it fit (the left caliper will not have this issue).

Also on the flex hose, the frame end mated correctly with the brake line, but would not go through the frame mounted bracket (hose boss was an odd hex/round shape, rather than the round shape of the hole). Again, a trip to the grinder to round off the hose boss solved that problem.

Lastly, I bled the right side, and pressure tested for leaks (none), and have a hard peddle. But the rotor is stuck after application of the brake. Opening the bleeder bleeds off a slight amount of pressure and the rotor can be turned. From this I assume I will have to remove the residual pressure valve in the master cylinder.

More on my trials and install tomorrow!

Plasticman