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MG MGB GT V8 Factory Originals Technical - no luck with my dana 44
|ok,,i have determined my rearend is a dana 44 out of post office jeep..its 51 1/2" wide outside hub to other outside hub,,from the differential to the back of hub there is approx. a 2" offset on the one side,, the rear isnt posi. & the more i think on it i think i'm going leave it that way [limited slip]after all i'm not drag racing a limted slip should be better for sporting purposes?? i've talked to D&D they have no disk setup for this rear they said its a great rear but they have concentrated on the s/10 rear because [tons more out there & tons more mods./brakes/gearing etc.]i've looked on jeep sites/at least 10[so far] disk brake sites/summit racing/jeggs..& cant find disk brake kit for this rear or for that matter any that will work with 14" wheels [i'm running 14" american racing wheels,,kinda a honeycomb type inside with 20? allen screws bolting that to an alum. rim..]HAS ANYONE out there done a disk brake conv. on one of these rears??[please help..]i'm on verge of giving up & changing out the wheel cylinders [probally with smaller ones as suggested by mr. guzman] then putting on an aftermarket 7" booster/gm type master cyl. or possibly putting on a new orig. type booster/master cyl. it would be cheaper!! but will i have GOOD brakes?? the shoes are new[but no self adjusters] i fixed the emergency brake riggen [works good now].the wheel cyl's. are shot[understatement].& i'm positive the booster/ms. is also gone.. thank you in advance for the responses..|
|What wheel lug pattern is your rear axle. Stock Jeep or MGB. If MGB you might be able to do a Saab rotor like Tony Barnhill did. If Jeep maybe you could have the axle lug pattern redrilled to MGB.|
|I'm not sure what it is you're after, but well operating drum brakes for the rear of the MGB, even with a V8 conversion, should be adequate for all road driving. A V8 doesn't add any significant weight to the vehicle. |
You would only need discs on the rear after you have significantly upgraded your front brakes and if you encounter fade problems from intense driving.
Just fix up what you have.
i agree with Edd --I am using D&D chevy rear end with drum brakes --stock MGB discs on front on my Ford 5.0L conversion for last 3 years over 35 K miles and find I perfectly adequate brakes for spirited road driving. I had it on the track in MI in 2003 and found no fade in the laps I did --so I am happy with this set up. I think people over worry about braking --brakes are only as effective as the rubber that contacts the road.
my 2 cents
Find a '95-'98 Grand Cherokee with a Dana 35 and do some measuring. Or if it belongs to a friend or relative, see if your rear wheel will fit over the rotor/caliper assembly. If so, read this link I found:
Gil wrote: "I think people over worry about braking"
I second that (as long as the brakes you have actually work.) One thing you definitely don't want is rear brakes that lock-up before the fronts. It's not hard to check, especially if you can get someone with a video camera to photograph you. Find an empty parking lot and do fake panic stops. You might want to experiment with wetting down the asphault too. Don't get carried away and flat-spot your tires.
|Hello Jim /washington the lug pattern has been altered from 5 lug to stock 4 lug mg pattern.. Ed in calf. i just want decent brakes[currently scarey!!] pedal goes 2/3 way to floor but then brakes do work but you gotta stand on em[mind you i'm 6' 250lbs.]at times i worry i'll blow out a line[done that on my chevy truck..]fronts cross drilled & v/8 pads[so the p.o. told me]. carl /tenn. i think my brother in law has one of those but the post office jeep rear is [according to 2 aftermarket outfits 1 of which,, teraflex, does jeep only stuff.] are different,what the difference is i dont know?? Curtis /co. most of my stops ARE panic stops 1 from goin to DAM fast & 2 from the pedal going 2/3 way to floor,,i'm not sure these brakes will lockup? scared to try & find out afraid of blowin out a line,done that on mountain in my chevy truck[made it home] & scraped out my shorts!!we'll see what others might say on this post,,i hate to spend thousands on disks,,smaller wheel cyl.'s & a new master cyl./ booster[need this anyway]is probally what i'll do 1st. there is a proportening valve but it doesent seem to do anything..THANKS to all who respond...|
|Denny, there is a short discussion in an British V8 newsletter that was written by Dan LaGrou of D&D Fabrications a couple of years ago. Following his instructions I recently completed a modification of this axle for my '67 tourer. While not a simple project, It does turn out nicely. I made a simple bracket to incorporate a stock MGB parking brake cable. The modification requires the use of a Wilwood rear disc brake kit for early 4 lug Mustangs. This kit requires a bit of machine shop work, as well as some welding on the axle housing. The Dana 44 is very strong for its size, and used ring and pinion sets in ratios appropriate for MGB's can be had for as little as $15.00 on Ebay. Posi ring gear carriers are nearly always available. I haven't got my car on the road as yet (short on time to finish the re-assembly of the 500 parts in little bags I put away 5 years ago when I started this Project!)Good luck, it sounds like you've got a lot of the work already sorted out. I have a really good set of drom brakes for this axle. If you want to go that way send me an email. cj|
|First, you really do not need the booster. It was added for little old ladies who couldn't reach the pedals. A big guy like you will have *no* problem with unassisted brakes. Second, drum brakes are fine even with monster front brakes. More than fine in fact. It's a matter of balance rather than capacity in this case, so your smaller replacement cylinders would be a very good start if your rears are locking up first, and personally I'd ditch the booster. A brake balance adjuster would be a very good addition. But if you must have rear discs, check out an early Mitsubishi Eclipse. Best E-brake setup I've seen yet, easy pad changes. You may be able to use an MG front rotor with it but as the Eclipse rotor is thicker I wouldn't advise it, probably better to redrill the Eclipse rotor. Making up caliper mounts should be no big deal. But you'd then have better brakes on the rear than you have on the front so you'd need to upgrade again.|
Does sound like your car might be dangerous in its current condition.
2/3 of pedal travel used up before anything happens could be indicative of:
Incorrectly adjusted rear drums, where the cylinders have to travel far before the shoes contact the drume. Check this adjustment. I don't know how it is done on you particular set-up but the info should be available somewhere. Drums are easy to adjust. Under this same category, it might be that the shoes are not mated to the drums well (concentricity). Turned drums and new shoes will fix this.
Or, the rear cylinders might be larger than the master cylinder expects and therefore has to push more fluid to, as you seemed to have guessed.
I think if you have larger rear cylinders, getting a good match between the rear shoes and the drums and a proper adjustment would minimize the cylinder size issue. Fix this first, then if there is still a problem, see if you can find a better match for the rear cylinders.
There is also the possibility of needing a good fluid bleed. When the pedal does travel the 2/3rds does it feel stiff then? If so, air in the fluid may not be an issue. If the pedal gradually squishes down as the brakes engage there is probably air in the system.
Get the rear end jacked up and have a buddy slowly push the pedal as you rotate the wheels by hand. This will give you a good feel for when and how firmly the brakes engage. It is also part of the adjusting process.
Leave the parking brake issue til last. You need to get this car stopping properly before you worry about parking.
One thing at a time.
Good luck !
|Hello Chris/tx. just this week i called D&D talked to the son he knew nothing of a disk setup for this rear,,i did download a article about this rear on B'S from the v/8 newsletter featuring dan[d&d] it stated they were going to fab. up a disk setup,but his son said that never happened ie;[they concentrated on the s10 rear].the m/cyl. & booster are orig. to the car[30 years old at this point] no shame thier shot,[probally gonna put new[oem] back on simpler& probally cheaper]as far as the wheel cyl's. go i'm afraid if i look at them the wrong way they'll fly apart[NASTY!!!]MR. BLACKWOOD you may something with the no booster needed, there is a proportening [balance] valve fitted it seems useless,i havent been able to lock up brakes at all. EDD/cal. i have gotten e/brake riggen fixed good now, ialso fitted new shoes, cleaned up area[stayin away from wheel/cyl's.] looked over& cleaned up springs & spent more time than i'll admit to adjusting,,however the rears seem to bind[shoes dragging slightly] then are very free so i may have a out of round condition..i've had air in lines before this isnt it,pedal goes way down but then ok,still very poor brakes..fellow down the road does restoration/body work/fab. says he'll have a look 2 people have said he's ok but i'm still kinda hesitant,in 50years of living i've only picked 1 good mechanic[great engine guy][wants nothing to do with my brakes]the rest i choose say 1 or 2 weeks then its 2or 3 months & usually the works 1/2 assed..the last guy who worked on it[or was supposed to] had it 2 months DID NOTHING said he didnt have time for toys?? i replied why didnt you say that at the start?? i took car,he said something about a bill,told him to JAM that,,thought there was gonna be a call to 911..thanks to all who have responded,& who have yet to reply..|
|Denny, the booster could be causing your problems. I've seen it happen, in fact I have a truck now with a marginal booster and you can't hardly apply the brakes manually at all and I'm seriously considering going to a hydroboost on it. I'm quite certain it would be safer to drive with manual brakes.|
Your slaves might not be as bad as they look, They generally have a pretty thick wall. If you spray them off with brake cleaner it shouldn't harm them, and you can pull back the lip of the boot to have a look inside, see how much junk is in there and get an idea of the bore size. If fluid runs out when you do this it means they are leaking. If not you can spray them out with the brake cleaner. Doing this will not harm them either as long as you don't spray junk back into the pistons. It gives you a chance to see if both pistons are moving. You should be able to push the tops of the shoes forwards and back to make the pistons move in the slave bore. Even really bad slaves can sometimes be reworked by honing and replacing the rubber parts. Kits and hones are available and pretty cheap usually. The hone can be run in a hand drill and it is an extremely low tech process. Your biggest worry is snapping off the attachment bolts and/or line fittings. Get a line wrench to use on the fittings.
The bore size will probably be quite a bit larger than the MGB wheel cylinder, likely to be around 1 to 1-1/8" or so where the MG is around 3/4". They can be sleeved with brass or stainless to resize them though. Several companies offer this service. Or, smaller identical slaves may be available. Those rear brakes are going to be quite a bit larger than the original ones. You probably have a 10 or 11" drum and 1-3/4" wide shoes. I don't remember exactly but the ones on the MG would be closer to 1-3/8 by 9 or so, making your current brakes a very significant upgrade. The shuttle valve you have between the lines is not likely to be a proportioning valve. More probably it is to activate the warning light if one circuit loses pressure. Adjustable proportioning valves are available from Summit and elsewhere. If it *is* a proportioning valve, then hooray for the PO! Especially if it is adjustable. If it is, it may very well be adjusted correctly, but your rear slaves may be taking so much fluid that the cause is lost even with the valve. A slave that size can easily take twice as much fluid as original and the stock MG master is not all that large to begin with. You could be losing half your pedal travel right there. hth
This thread was discussed between 13/01/2006 and 14/01/2006
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