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MG MGB GT V8 Factory Originals Technical - Installing the ford 8' questions
|The rear is almost put together, has anyone address the install in the British V8 Newsletter. Here are the questions.1- How do you hook up the rubber brake hose with the brass fitting to the MGB main brake line.2- Look like my drive shaft will be 1/2" short just from measuring both rears my driveshaft has a Ford yoke on it,do I just add a spacer or can you get different pinion yokes for the 8".3-Do the spring perches get welded parallel to the rear and I have it almost together will the heat from the welding hurt the new bearings in the axles, I would think not.4- How to hook up the e-brake I'm thinking of only hooking up one and doing some kind of splicing to the MG cable. I need help as soon as possible for it will help to have some knowledge before I get started. Guess I should of asked this all sooner but I am going to start it and I hope I can finish it. Thank you for any responce. Denny|
|Here are more I just thought maybe you guys with the Ford rear can E-Mail me your phone number. What about the rear sway bar does it clear the center section,or do I have to raise it up. The first question I should of asked Does the rear fit without any clearence problems. Denny|
|The questions keep coming into my mind. I am guessing you buy the factory Ford U bolts to mount the rear end to the MG springs. Denny|
|Is this a narrowed Ford 8" with Ford backing plates and brakes?|
Half-an-inch short drive shaft may be OK as is, but I think you are only guessing. Everything has to be assembled at ride height, then measured for the drive shaft.
Assemble the rear on the spring perches sitting on the springs and snug up the u-bolts. Whatever U-bolts you use, they have to go through the clamping/shock bracket. The rear weight of the car must be on jackstands under the axle, and the front of the car should be adjusted so that the car is as it would be sitting on the ground. Assuming you've adjusted the rear side-to-side where you want it, now you have to adjust the pinion angle. It needs to be parallel to the engine/trans centerline. Some people adjust it 1-2 degrees nose down - read up on this and decide how you want to use your car. Once all this is set up, then tack weld the perches to the axle. I suggest that the axles be removed prior to finish welding. I don't think I would have assembled the rear until this welding is done.
Other folks will have to comment on the remaining questions.
|Its a narrowed 8" with Ford backing plates and brakes. You do not think the MG spring perches are parallel to the pinion and if it is why not just do it like that. I should of looked at the ford perch before I cut them off. Denny|
|Jack Emery- MG Car Guys- built my narrowed 8" Ford rear. MG spring plates were used as were stock MG U-bolts. The pinion angle must be 1-3 degrees off otherwise the U-joints will not rotate & will quickly wear out. This is basic with all rear wheel drive cars. All welding should be completed & then the housing checked for true using a straight bar & dummy beaings and a dummy carrier. The last time I saw this done, the bar was 2 1/2" diameter about a foot longer than the housing, & it was all I could do to lift it. It is not uncommon for the housing to be slightly crooked & this must be corrected or the bearings will quickly wear out. |
I tried several ways of hooking up the parking brake & finally bought a kit make by Locar, a supplier of street rod products. Some welding on the link to the handle was required to get the correct travel.
To join the MG brake lines to the Ford lines, I used a short Airquip line made for the MG system and an adapter fitting to match the line to the Ford fitting.
Drive shafts must be the correct length. They can be shortened, but if too short, it looks like a new shaft. The ends can be reused, but a new tube will be required. I would never trust a spliced tube, & I am not aware of any spacers that could be used.
|Jim the tubes on the MG and the Ford seem different size,and do you use the bump stop and anything else that might come off over to the Ford. The Locar part do you remember which one,or are they universal. I dont know what an Airquip line is where do you get it. The drive shaft where it hooks up to the yoke couldn't you put a big 1 piece spacer in at that point.|
|What Jim is trying to say is correct, but I think the terminology is off a little. Universal joints are designed to travel through plus and minus a few degrees during shaft rotation - otherwise the needle bearings wear into a localized spot on the cross and bearing cups. The pinion angle (not the u-joint motion angles to which we are referring) is the angle through the centerline of the pinion gear shaft relative to the centerline of the engine/trans. The two centerlines should be parallel, but not directly inline (or you will get localized wear in the u-joints).|
If you are sure that the centerline of your new engine/trans installation is parallel to your original engine/trans, then you can duplicate the original pinion-spring perch setup. But why do that when you can measure it and be sure?
Doesn't your Ford pinion yoke have a flange that accepts u-joint cups held on with u-bolts? If so, where would you put the spacer?
I could be wrong, but I beleive that Jim's reference to Airquip may be Aeroquip which is a hydraulic hose and fitting manufacturer. Using them (or Parker Hannifin, or others) you can get a hose with the correct fittings on each end.
|Wayne if I jack up the back of the car lets say 8" than I have to jack up the front 8" measuring off the body somewhere in the front and back. The spring perches are loose on the axle and the center section [pumpkin] is mounted in place. The two center lines should be parallel,but not directly inline, does this mean the pumpkin could be higher or lower but at the same angle as the engine trans. Denny|
Denny, I like all the advice Wayne's given. But can I give you a general suggestion? Probably in your town, and certainly in your county, there's a Dana-Spicer shop. You're at the right stage in your project that you should meet them. Most Spicer shops do a steady business making driveshafts for heavy trucks - but they'll have the expertise to answer all your questions.
My local shop made me a gorgeous machine-balanced driveshaft for about 85 bucks. Don't even think about making your own! They did it while I watched one day at lunchtime. (I was a little late getting back to work that day.) My point is that making and balancing driveshafts is a quick job for someone with the right machinery and skills.
Spicer is, of course, the first name in universal joints. They'll probably also be happy to sell you whatever u-bolts you need. (I prefer factory-made ones over the one's they may offer to custom-bend for you though. Factory-made u-bolts are heat treated.) (MG u-bolts wouldn't fit on my 8.8 axle.)
Finally, here's something that's good to know. If you screw-up and get your spring perchs welded-on a few degrees out of optimal alignment (as I did), it's easy to buy aluminum wedges that're made for the purpose of shimming the whole axle assembly to the correct angle. Guess who sold them to me.
(Usual disclaimer: I don't have any financial interest in Dana-Spicer...)
|What Wayne & Curtis said.. The flex line was part of a 3 piece kit sold by Moss & others including flex lines for both front calipers.|
The Locar piece is a "universal" kit sold by Locar through street rod/speed shops.
The 8" Ford & MG housings are almost identical at the point where the U joints fasten, or at least close enough.
The bump stops are on the chassis rails of the MG & need no mods.
The rear pinoin can be above or below the transmission output, & 1-3 degrees out of parallel.
|Curtis that is good to know about the Dana-Spicer. The shims make me feel a lot better. My conversion is three yeays old and I guess I just didn't want to buy another driveshaft. I will use my ends and get another tube,he also said that as long as I have at least one inch into the trans that will be enough. Jim my 8" axle does't taper down like the Mustang rear I looked at. I meant the plate that the bump stops hits, that are on top of the axles can you reuse these. You guys are giving great reference for future rear end installers advice that I haven't seen before. I will let you all know how it goes I thought I could do all the work in about two week's,but with some of the parts you have to order who knows. Denny|
|Denny, in answer to your question to me - yes. Just be sure that the rear springs are supporting the weight of the car.|
Denny asked: "I meant the plate that the bump stops hits, that are on top of the axles can you reuse these?"
Yes, certainly. I was able to reuse them with my 8.8 axle. Seems to me I had to modify them just a little with a hacksaw or side grinder... (My memory is fading.)
|IIRC, the tail of the transmission should be tilted down to the tune of two to three degrees and the nose of the rear axle should be tilted up the same two to three degrees, at rest with the weight on the car.|
Jegs and summit sell a good cheap angle finder for just this purpose.
|If I put a protractor on the face of the transmission where the driveshaft mounts and say its pointed 2 degrees up,and I put my rearend on a level surface and point the face where the driveshaft mounts 2 degrees down then I have what I want correct. This sound to easy so it possible couldn't be right. Today I am going to do my first testing of the installion of the rear. To you folks that means stand by more questions. Denny|
|Just got done looking at the car on a lift and the T connection that hook the brake lines to the wheel cylinders and then to the master cylinder why can't I just weld a bracket to the Ford axle and reuse that instead of the Ford T. Denny|
If you have 2 degrees up and 2 degrees down, then your drive train will be parallel. Youn want to have your drive line 2-3 degrees out of parallel so the bearings in the U-joints will rotate and not qickly waer in one spot & fail. The protractor used with a level should give accurate results.
You can use the original MG bake lines & weld a bracket to the new housing, but you will find that the Ford & MG fittings are not the same. You will have to find some sort of adapter. It is easier to use the Ford lines as the are already bent and are the correct length. If you make the transition at the flex line, you will only need 1 adapter. You can go to a shop that makes hydraulic lines & get a line the length you need with the correct fitings. Ask the guys that do your drive shaft for a recommendation for a hydraulic shop.
|Sorry Jim, but what you are saying is not correct. You want the centerlines to be mis-aligned, but parallel, so the u-joints travel through 2,3 or 4 degrees. If you do as you say, there will be a vibration in the driveline. Sometimes when setting up a drag car, you nose down the pinion centerline a degree or two because under hard acceleration, the pinion climbs the ring gear and the misalignment goes away.|
|Wayne, you may be correct. I have built 6 MG V8 conversions & never replaced a U-joint. My cars are daily drivers. 1977 roadster 270,000 miles, 1974 GT 230,000 miles, 1966 roadster 63,000 miles, 1973 GT 20,000 miles this year. The other 2 cars were not mine & milage is unknown|
|Jim, I won't argue with success - you've obviously done good work there. But I also know what I know; nonetheless you had me second guessing myself and I dug up these references just for reinforcement:|
This thread was discussed between 18/07/2005 and 25/07/2005
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