rambler roadster T5 research notes

JULY 2017 NOTE: below is the notes and research i did to install a T5 into the roadster. i've kept it because it contains much information on paths not chosen that might still be useful.

ongoing doco of conversion from AMC T14/T96 to Ford T5z. this page is mere glorified notes for the project, not yet a how-to. this applies to my own peculiar project, a 1961 rambler american, AMCs 01 chassis series, that i've hacked into a rodaster, and in which i am retaining the Nash/Rambler 195.6 OHV engine and it's mating bell housing, which is intimately tied into the chassis in a difficult way.


195.6 OHV volcano crankshaft flange, in junk motor, with flywheel attached

199ci six, 64 up crankshaft flange, crankshaft part only, no flywheel

there exist two different 195.6 (OHV and L-head) crankshaft flywheel mounting flange styles; volcano and flat. it is generally agreed that the volcano is on earlier manual transmission car crankshafts, and flat flange on automatics and all transmissions 1963 up. the important point here is that the flange type determines pilot busing fore/aft position, relative to the back of the engine. on flat butt cranks the rearmost edge of the pilot bushing is 1/2" above/past the bellhousing big end; volcanos protrude 1.25". the pilot bushing position is forward for flat butt cranks (flush with the flange). the volcano protrudes well past the mounting flange face, pushing the bushing decidedly aft (protrudes beyond the flange by 3/4").

the crankshaft pilot bushing situation presents two interrelated problems; depth, and diameter.


by 'depth' i mean the position of the very rearmost edge of the pilot bushing. the pilot bushing is pressed into its hole into the end of the crankshaft, and this fore/aft, longitudinal position determines how long the transmission's clutch shaft must be, for the tip to ride in the pilot bushing.

the problem

if you have a volcano butt crankshaft engine, there is no problem with depth. the depth problem exists with the flat butt crankshaft.

the solution

buy a volcano adapter from Galvin's AMC Rambler Parts. (alternatively you may be able use the less common 7.85" long input shaft version of the T5, but i am not pursuing that path.). in any case it would be wise to measure the bell housing depth first, and make sure the assembled length will be correct; see below. if it's a different depth/part number, please let me know so i can document it. Galvin's adapter adds 0.75" stickout to the flat crank, for a total of 1.25" stickout, the same as the volcano butt crank.


the problem

the volcano adapter snout accepts a bronze pilot bushing, Dorman 690-004, which is .628" ID and .815" OD. this is a very small thing; the flat butt crankshaft, and all of the 1972-up crankshafts six and eight, use a much larger OD bushing, 1.05", that allows for a wide selection of bushings or at worst, modification of an existing one.

the annoying thing is that the small OD of the bushing hole limits this engine to that one pilot tip diameter. the bad news is that T5 transmission clutch shaft pilot diameter is .590". there is simply not enough bronze in the bushing to bore out to that diameter (it would leave the bushing wall under 1/16").

the solution

there is no simple fix. the least-annying path is to modify the T5 transmission clutch shaft, turning the tip diameter down to the AMC spec of .625". this will then fit into the "stock" pilot bushing in the either the factory voltano butt crankshaft, or into the volcano adapter.


as far as i know no one has ever tabulated nor compared or even measured 01 series bell housings. time to start, see below. if you care to contribute, i'd appreciate it. the part number can be found inside the bell, just below the throwout fork pivot, cast into the bell. you might have to wire-brush the gunk off to see it.

in the 01 series chassis the bell housing also supports the rear motor mounts; there is no "transmission crossmember" nor true transmission mount in this chassis. like an old Y-block Ford car the transmission dangles in free air off the back of the bell. without reengineering the chassis for a rear transmission crossmember and mount (which honestly wouldn't be that hard to do) you are stuck with this odd, tiny little bell that fits in the hole, accommodates only the small 12" flywheel setup and has only one (1) manual transmission option: the Borg Warner T96. you have not heard of that transmission before for good reason. it sucks.

i suspect that there are different-depth bellhousings though i find no evidence of them in the factory parts catalog i have (1963). given that there is not one documented instance of a T96 transmission clutch shaft other than the standard 7", and that both flat and volcano cranks indeed have manual transmissions behind them, the difference must be in the bell housing.

01 series bells are easy to identify; they have bosses for motor mounts at about 4 o'clock and 7 o'clock, and a stamped removable cover below (necessary to gain access to the motor mount bolts). it's also very small.

Rambler early six bell housing dimensions
part number depth application notes
3145345 X3 6.625 (6-5/8") T96, flat butt crank


center two are 195.6 small 12" flywheels. above and below, 64-up large 14" flywheels.

the problem

the short of it here is that you cannot install a T5 into an engine that has the flywheel drilled for the small, Nash/Rambler, 8" clutch (it actually measures about 8.5"). first, replacement discs ar eno longer available, and absolutely no 8" disc with suitable drive spline has ever existed. believe me, i looked. "most" pre-1964 Rambler Americans, which are really restyled Nash Ramblers, use the small clutch, though (1) there was a "heavy duty" option for the larger 9" clutch (actual measurement, 9.25") and (2) all other six cylinder AMCs (the 10 and 80 series) used the 9" clutch.

the 195.6 and some 199/232 flywheels are just over 12" diameter at the ring gear teeth. some 199/232 flywheels are approximately 14" diameter and while they will bolt onto the crankshaft, they won't fit inside the bell housing.

the solution

the small flywheel drilled for the 9" clutch is not rare. you can locate one, or drill/have drilled what you have. that is the only difference between the two. many 195.6's have one, and i think some 199/232 powered AMC cars through 1971 may also. it's easy to check by measuring across two clutch cover mounting bolts: the 9" clutch mounting bolts are 10.5" across, the 8" clutch mounting bolts are 9.5" across. if you are going to have it drilled you might as well use the whole 1993 Ford Mustang 2.3L clutch kit' see the CLUTCH section below for details.


T14 (T96) shaft sticks out 0.375" past bell face.

SR4 (T4, T5 short) shaft "stickout" is minus .475"

here are some pics and basic dimensions for fitment of a T5 (with an SR4 standing in for a T5, for now) behind the Modern Drive Lines Nash/Rambler adapter for the early six. this is not going to be a bolt-in job, to say the least.

at the moment i have only an old AMC SR4 transmission, which is compatible with (some of) the T5 as far as the bell interface goes. so i assembled parts on the bench for initial measurement; the T14 on a 1963 01 chassis bellhousing (suitably modified to accept the relocated lower bolts) and the SR4 on the MDL adapter on the same bell. it is clear that there are going to be issues.

below is what we're working with, enginewise. this is obviously the flat-butt crank (not volcano butt). the volcano butt would solve one problem, below, possibly... i will be using the front mounting face of the bell housing, where it bolts to the engine, as reference surface for all clutch depth measurements. her can be (barely) seen is that the outer edge of the pilot bushing protrudes past the bell mounting surface by approximately 7/16".

the T14 is a stand-in for the T96. i drove this combination, it works and the important measurements here are identical (the T96 is in the iron pile at the moment.) with the bell bolted to the T14 you can see that the tip of the clutch shaft sticks out past the bell mounting surface by about .375". this means that the pilot portion of the shaft is inserted into the pilot bushing about .875". measured from the bell/engine mount surface also, the root of the clutch shaft splines is at1.625", and the outer lip of the throwout bearing sleeve begins 3.25" in.

with the SR4 things are not so good. however, this is the "short input shaft" transmission, i think the same as the Ford 1993 and earlier dimension for the V6. due to the adapter, the clutch shaft tip is recessed 0.5" from the bell/engine mount surface, splie root is 2.0" in, throwout bearing sleeve begins 3.0" in. ("long input" shaft length is in my notes, i'll edit this later.)

the next area may be a deal-killer for some, but not for me: the SR4, and certainly the T5, is much fatter than the old T14/T96, upwards. the top of the T14 case is no more than 1-3/8" above the centerline of the top transmission bolt, and it is short, the case only 9" long from bell to tailhousing start. the SR4 body/case rises 3-3/8" above the top bolt centerline, and extends 19" from the bell to where the tailhousing portion begins. this means that the SR4 wants to exist where there is floor pan/transmission hump. the solution for me is to make a new hump. but in a car with carpeting and all that, the interior will have to be worked on to match.



the only manual transmission available for all early-six cars is the excreble T96, or only faintly more interesting, T96 with R10 overdrive. if it was any good at all we wouldn't be doing all this work, would we. it sucks. this transmission has a 1" x 10 spline clutch input shaft.


AMC adapted the Jeep T14 to passenger car use for 1968 (i think). the input shaft dimensions (1" 10 spline) are identical to the T96, and is bell compatible with the T96, except for the lower two bolt holes. this can be accommodated (i did so). the T14 is reliable, all synchromesh.


assembled pilot bushing penetration. the simple calc is:

depth = shaft length - bell depth - adapter thickness + crank flange stickout
  shaft length bell depth adapter thickness crank flange stickout (type) pilot tip penetration notes
T96 7 6.625 0 0.5 (flat) 0.875 stock
T5 7.15 6.625 1.0 0.5 (flat) 0.025 no depth
T5 7.41 6.625 1.0 0.5 (flat) 0.285 not adequate
T5 7.85 6.625 1.0 0.5 (flat) 0.725 good
T5 7.15 6.625 1.0 1.25 (volcano) 0.775 bingo!
T5 7.41 6.625 1.0 1.25 (volcano) 1.035 too deep

critical transmission input shaft measurements

  A B C D index diam. spline pilot tip diam. bearing retainer snout diam. T.O. bearing sleeve ID T.O. bearing sleeve 'fork' diam. T.O. bearing face to fork contact
this is the only manual transmission available on all AMC/Rambler sixes through 1964, with rare exceptions: T96J, T86.
T96 7 1.625 2.0 3.5 4.25 1 x 10 .745 1.312 1.316 1.525 1.25
"plug compatible" at the bell housing with the T96, except for the two lower mounting holes.
T14 7 1.625 2.0 3.5 4.25 1" x 10 .745" 1.312 1.316 1.525 1.25
this is a Ford transmission used in 80's AMC cars. it is "bell compatible" with short-shaft T5 and T4.
SR4 7.15 1.875 1.5 4.0 4.842 1-1/16" x 10 .590" 1.435 ? ? ?
1993 and earlier, various; a common application is 1979 Ford Mustang with 3.8L V6.
T5, 7.15" shaft" 7.15 1.25 1? 4.625 4.842 1-1/16" x 10 ? ? ? ? ?
1994-2004?, various Ford. the bell housing depth changed only, the additional length of the clutch shaft is the portion under the bearing retainer; the spline and pilot tip is the same as "short shaft" T5.
T5, "long shaft" 7.41 1.25 1? ? 4.842 1-1/16" x 10 ? ? ? ? ?

bearing retainers are easily modified or replaced with aftermarket including some latitude on diameter.


the Nash Ramblers use a so-called 8" clutch (it's more like 8.5" diameter, measured). no new parts are available, and good cores for rebuilds are scarce, and in any case, the driven disc doesn't fit the T5. after much scrounging and help from the AMCforum i ended up with a Ford part that fit under the 8" pressure plate but had T5 splines. the "small six" (195.6's, pre-72 199/232) has a smaller diameter flywheel, and it will be drilled for either the 8" or the 9" AMC pattern clutch. though even the 9" is increasingly hard to get, it's not yet as bad as the 8". this same Ford disc (below) will fit this, too. both clutches were used in the Nash-based Rambler, the smaller as typical and the larger as heavy duty, and in the E-Stick system. other than the diameter and bolt pattern, both have the same running height relative to the flywheel, same release bearing, fork, etc.

the 1993 Ford clutch assembly -- driven disc, pressure plate, release bearing -- is tantalizingly close to fitting as-is on the Rambler flywheel... with a few differences. the bolt circle pattern is about a tenth of an inch smaller -- it *almost* lines up with the existing holes; see the photo. second, the height of the release fingers, relative to the flywheel surface, is lower, eg. closer, and so the clutch fork pivot in the bell housing would have to be raised about 3/8 -- 1/2" to compensate. no big deal as there are aftermarket parts expressly for this purpose. the only reason i did not do this in my installation is ecomonic -- i have two perfectly good rebuild 8" clutches on hand. i have the parts on hand here and it does line up. ymmv.

Aug 2017 note: AMCers came up with two other possibilities for "modern" donors -- Sachs clutch replacement kits for Volvo 122S and Alfa Romeo Spider. the clutch discs appear to have the correct spline (1 x 10) and diameter. spline depth offset unknown. the pressure plate likely will not bolt on, looks similar to the Ford part described above, and would likely need redrilling.

here are some pics to show actual sizes of the various AMC clutch parts.

8" clutch on the left, 9" on the right.

8" part actual measurement

8" part actual measurement

9" part actual measurement

9" part actual measurement

the winner for me was this Sachs clutch kit, for a 1993 Ford Mustang 2.3L inline 4 cylinder. the entire kit of new parts -- pressure plate, driven disc, throwout bearing, alignment tool, and grease -- cost less than a single rebuilt AMC driven disc! the spline is the required 1-1/16" x 10 splines, and the correct diameter to fit the rambler 8" pressure plate. as yo ucan see in the photos below, the bolt circle is tantalizingly close as-is, and a competent shop could drill a new bolt pattern on a good rotary table drill press or mill.

AMC 9" butted up against the '93 Ford Mustang 2.3L pressure plate to show the near-compatibility of the bolt pattern...

Ford 8" driven disc on Ford pressure plate

AMC 8" driven disc on Ford pressure plate

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