Sprinter 4WD Conversion Idea, GMT-800 IFS.
- Thread starter luthj
- Start date
luthj
Engineer In Residence
Ran the van down the road for some fuel, and then did a loop of the local roads to adapt the trans. No issues other than vibration mentioned before. A quick check with my angle finder says the pinion needs to be another 4 degrees higher to match the Tcase. I ordered some generic pinion shims. I will probably need to modify my lift blocks a bit, but its not like I can find sprinter specific shims!
Front end parts are in the mail. I may have to move some stuff out of the garage so I have space to work.... Actually, maybe I should just make a big table out of all the plastic totes... Its about to get BUSY. I may just need to take a day off work to relieve the itch...
Front end parts are in the mail. I may have to move some stuff out of the garage so I have space to work.... Actually, maybe I should just make a big table out of all the plastic totes... Its about to get BUSY. I may just need to take a day off work to relieve the itch...
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Mwilliamshs
Explorer
All the parts stores rent them. Try theirs and if it works, keep it.
Len.Barron
Observer
worth the $130 a piece for new loaded LCAs!! LOL!!
luthj
Engineer In Residence
I would generally agree. All the new ones I am finding don't have the middle cross piece between the legs. Not quite as strong.
luthj
Engineer In Residence
A local (well 30 minutes away) shop said they could build me a 75" driveshaft. They apparently do high performance vehicles, so they offered me carbon fiber at first... A bit rich for my blood. So 4" aluminum it is. They don't stock truck yokes, I will need to mail them mine when they are read to balance. I suspect the lead time will be several weeks.
If you haven't handled domestic 1 ton truck brakes, they are a bit heavy... I may have underestimated the added weight by 50lbs or so. I am still 50/50 on if the MB master cylinder is going to have enough volume for these big boys. If not I have done some preliminary measuring, and I think the GM 1500 MC should bolt up with an adapter plate. Though the pedal ratio is going to be a bit off.
I plan on getting the LCAs ready over the weekend, and putting a few more coats of chassis saver on the suspension parts. I don't want to do this ever again, especially not for rust! I will also do a couple of test flares on the brake line, to make sure its going to work properly.
If you haven't handled domestic 1 ton truck brakes, they are a bit heavy... I may have underestimated the added weight by 50lbs or so. I am still 50/50 on if the MB master cylinder is going to have enough volume for these big boys. If not I have done some preliminary measuring, and I think the GM 1500 MC should bolt up with an adapter plate. Though the pedal ratio is going to be a bit off.
I plan on getting the LCAs ready over the weekend, and putting a few more coats of chassis saver on the suspension parts. I don't want to do this ever again, especially not for rust! I will also do a couple of test flares on the brake line, to make sure its going to work properly.
Len.Barron
Observer
a lot of the hydroboost equipped 2500/3500's have a 1 7/16" bore Master Cylinder, they move a lot of fluid..
Mwilliamshs
Explorer
Yeah 1500 MC + one ton brakes doesn't add up. Seriously doubt a half-ton has the same diameter MC as the 2500.
vintageracer
To Infinity and Beyond!
check out brakes from a 1500 HD Chevy/GMC from 2001-2004. Half ton truck with 3/4 ton axles and a 6.0 engine. May work for you.
luthj
Engineer In Residence
I've got the specs and math on my desktop. From memory the 1500 and 2500 have the same bore calipers at about 2". The MCs vary from 1.35" to 1.46" depending on rear drum/disk and vacuum/hydroboost config. Pedal ratios are the same I think. The hydroboost offers more assist than the vacuum booster. The sprinter has a fairly low numeric pedal ratio, which may be troublesome depending on total stroke.
The mb MC should have enough displacement to stroke the caliper and provide good pressure. But it's a close enough that I won't know unless I can measure total travel.
The mb MC should have enough displacement to stroke the caliper and provide good pressure. But it's a close enough that I won't know unless I can measure total travel.
luthj
Engineer In Residence
Details below. I can't say for certain, but the parts catalogs seem to indicate that the MB MC has different diameters for the front/rear pistons. The front is 1.4" while the rear is 1". That would make sense given the single vs double piston config used stock.
The pistons on the MB front caliper are smaller. There is some conflicting information, as the larger 285mm rotor supposedly has a smaller piston (45 vs 51mm). But I can't be certain. Both MB applications appear to use the same MC though. As you can see the effective torque on the MB setup is lower, thus they must use a higher pedal ratio than I initially guessed. So my only major concern is that the MB MC has enough stroke for a worst case scenario with the pads retracted more than the typical 1mm or so.
The pistons on the MB front caliper are smaller. There is some conflicting information, as the larger 285mm rotor supposedly has a smaller piston (45 vs 51mm). But I can't be certain. Both MB applications appear to use the same MC though. As you can see the effective torque on the MB setup is lower, thus they must use a higher pedal ratio than I initially guessed. So my only major concern is that the MB MC has enough stroke for a worst case scenario with the pads retracted more than the typical 1mm or so.
Vehicle | MC Bore | Bore (MM) | Front Caliper Dia (x2) | Front Caliper Dia (x2) (MM) | Pressure Ratio | Rotor Dia (MM) | Rotor Dia Ft | Effective MC torque LB-Ft per lb |
Burb 2500 hydro | 1.46 | 37.00 | 2.24 | 57.00 | 1.54 | 325.00 | 1.07 | 1.64 |
Burb 1500 vacuum | 1.34 | 34.00 | 2.00 | 50.90 | 1.50 | 301.75 | 0.99 | 1.48 |
Sprinter 2500 | 1.42 | 35.94 | 1.77 | 45.00 | 1.25 | 285.00 | 0.94 | 1.17 |
MB MC with 2500 Caliper | 1.42 | 35.94 | 2.24 | 57.00 | 1.59 | 325.00 | 1.07 | 1.69 |
luthj
Engineer In Residence
My relentless google searches have final borne fruit. GM parts 5001719-1743M, 922983-6820, 15128092, 15077434. These are 75.25" C-C length if the internet is to be believed. Unfortunately they are 1410 joints. But for the reduced cost, I don't mind using 1350-1410 conversion joints, and carrying a spare. The dorman version is 460$ delivered on closeout. Add another 50$ for combo joints, and I should be done. Its 5" diameter though, so I may need to move the fuel tank bracket.
This is my first exposure to brake calculations, but I think you forgot to square the value in the 'Pressure Ratio' column, which I'm interpreting as the force ratio between force applied at the MC to force at the caliper piston which is proportion to the piston areas.
P = F1/A1 = F2/A2
F1/F1 = A1/A2 = Pi D1^2 / ( Pi D2^2)
So consider the first case
A1 (@ caliper piston ) = 2* (2.24)^2 * Pi (multiple by 2 for (2) piston caliber)
A2 ( @ MC) = (1.46)^2 * Pi
A1/A2 = 4.7
P = F1/A1 = F2/A2
F1/F1 = A1/A2 = Pi D1^2 / ( Pi D2^2)
So consider the first case
A1 (@ caliper piston ) = 2* (2.24)^2 * Pi (multiple by 2 for (2) piston caliber)
A2 ( @ MC) = (1.46)^2 * Pi
A1/A2 = 4.7