Flexplate is not fits the torque converter
- Thread starter Achill
- Start date
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I have an engine 5.9L from Jeep Grand Cherokee 1998. In summit it's shown as:
Engine / JEEP
5.9L/360
Mopar small block Magnum
Looks like I'm back to basicsis it Magnum or not? I don't want to buy the third wrong flexplate
Is there a way to identify if it's Magnum or LA visually? I have doubts now
69_340_GTS
Well-Known Member
Magnums have 10-bolt valve covers. The Magnum intake manifold-to-head bolts point straight down. LA has the intake bolts perpendicular to the head. If you pull a valve cover, you'll find pedestal-mounted rocker arms on a Magnum instead of LA shaft-mounted rocker arms. If you remove the intake manifold you'll find roller lifters on the Magnum. Front end parts like water pump, alternator, p.s. pump, had serpentine belts on the Magnum (however LA parts also fit). I'm sure the serial numbers stamped in the block would tell you something, but I don't know what you'd look for.
CudaFactHackJob
Well-Known Member
I'm pretty sure only the mpfi magnums have vertical intake bolts. The throttle body magnums have same as old 318.
Hi, contacted the magnumswap and looks like I have the wrong torque converter. What I have is "Torque Converter, Saturday Night Special, Mopar, Torqueflite 727, Each" TCI Saturday Night Special Torque Converters 141500. that's why flexplate ATP-Z332 is not fits my combo - Magnum (now have no doubts) and 727 transmission. Now I want to try to install the original toque conv from jeep grand Cherokee, I've checked at summit - B&M Tork Master Torque Converters 10417 - this one is fits both - Torqueflite 727 and 46RH. What do you think, can I swap my TCI Torque conv to this one 46RH? In this case I'll use the ATP-Z332 flexplate and HOPE that vibration will go away
CudaFactHackJob
Well-Known Member
I would think that use of the flexplate with the smaller cutout in post #67 would work with a non weighted converter.
Bobzilla
Well-Known Member
Please post a picture of your engine so we can see the intake manifold. This will verify it is a Magnum engine. It should be if it was from 98 Cherokee.
Please tell us what vibration dampener is on the front of the crankshaft.
If this is a completely stock 5.9 liter Magnum engine, and the torque converter in the original post is being used, you must have B&M 10242 or equivalent, as posted by 70aarcuda on the first page of this thread, post number 14. This is the correct flex plate for 5.9 Liter Magnums with a neutral balance torque converter.
The 10242 is not available currently. None of the B&M flex plates you have are correct.
You can make the correct flex plate using a template to copy the cutout in the 10242. Hughesengines.com is selling one like this but it’s expensive.
Please do not buy any more parts until these questions are answered. Hopefully we can figure this out.
Thanks a lot for your answer! appreciate that!
1. Now I have no doubts that I have magnum.
2. Front dampener I have is this MOP P5007187AB DAMPER, MAGNUM 5.9 EXT BALANCE NO PULLEY OEM EXTERNAL BALANCE FOR 93-03 5.9L MAGNUM ENGINES
3. Regarding the B&M 10242 - more than sure that the one I've installed is equal to this.
Some photos and my logic:
1. You can see (first picture) that 10236 (that for 360LA) and 10237 have the same geometry but 10237 have the less weight offset as it requires by Magnum (magnum should have less weight offset than 360).
2. Picture 3 - 10237 is lays on the ATP-Z332 (that's originally comes with Magnum on Cherokee 5.9L. I've marked with white the cut
3. Picture 2 - 10237 and ATP-Z332 lays near each other, it's not so visible but with white I've marked not only the cut but the weight on the ATP-Z332 (that on the other side of the plate and not visible). This picture shows that the weight offset, meaning CUT on 10237 is placed absolutely opposite to the weight placed on ATP-Z332.
So my 10237, that's installed not is have the right placement of the weight but something wrong with the pair of flexplate and the torque converter. Originally there should be 10 inch and I have 11 inch. What I'll try is to take out my converter, try to check it's balance, if the balance is ok, so I'll try to change the converter that Originally comes with Grand Cherokee (46RH) in that case ATP-Z332 should work (with one hole adjustment)
P.S. I've found on hughes this flexplate for Magnum and 727 - BMM 10230-MAGBAL
727 TRANS FLEXPLATE 11.100'/10.010' B&M
B&M SMALL BLOCK FLEXPLATE BALANCED TO MATCH CHRYSLER 5.9 COUNTERWEIGHT
any ideas what's the flexplate is it?
Hi, do you have a picture of it and the measurements?
B&M Flexplates 10242 - on the picture it's looks like B&M 10237.
Bobzilla
Well-Known Member
10237 is NOT equal to 10242.
BMM 10230-MAGBAL is a B&M 10230 the Hughes cuts to match the discontinued 10242. They cut the proper size and shape notch into the 10242.
For reference, I will add a photo of the 10236 LA 360 balance on top of a 10242 Magnum 5.9 liter balance.
It is normal for the cutout on the B&M flex plate to be opposite location of the factory Magnum flex plate weight. That makes the side with NO cutout heavier to match the position of the weight.
BMM 10230-MAGBAL is a B&M 10230 the Hughes cuts to match the discontinued 10242. They cut the proper size and shape notch into the 10242.
For reference, I will add a photo of the 10236 LA 360 balance on top of a 10242 Magnum 5.9 liter balance.
It is normal for the cutout on the B&M flex plate to be opposite location of the factory Magnum flex plate weight. That makes the side with NO cutout heavier to match the position of the weight.
Bobzilla
Well-Known Member
The 10237 looks similar to 10242, but they are not equal.
So how I see it - flexplates:
1. 10236 (for 360 LA) have the biggest cut
2. BMM 10230-MAGBAL or 10242 is for Magnum and it's have a bit smaller cut
3. 10237 is have even smaller cut than 10242, so needed to be "adjusted"
4. All mentioned flexplates above have the similar bolt pattern.
What I have to do is to cut from my 10237 a bit more to get closer to 10242 in term of weight offset? How much should I cut? in mm? maybe there a chance to get a template? how to cut not too much and not too less?
R u sure u have a magnum and not a LA with a mag balancer on it? Maybe a LA crank in a mag? Maybe a part or the whole rotating assambly was changed? U have been on this way to long to not have it figured out. Post pics of the block, Casting numbers, dates,intake, front and rear of crank Kim
Bobzilla, I'm comparing your picture and mine. On both the 10236 is on top, in your pic on top of 10242 in mine - 10237. Looks like I have to cut a bit more. but would be superb to know precise difference if you can share. Thanks a lot in advance!
CudaFactHackJob
Well-Known Member
Plan on cutting just a little bit but not too much.
Bobzilla
Well-Known Member
I will try to get some measurements today and final weight so can modify one of your current flex plates.
thanks a lot! the car is on the lift without the transmission waiting for the flexplate
All I need is the distance between these two lines! Thanks a lot in advance!!!
Bobzilla
Well-Known Member
Notice in that previous picture you marked up the flex plate is sitting with “ENGINE SIDE” down.
The middle area you marked on a 10242 is about 0.325” larger than a 10136.
The top area at the point of the notch on the 10242 is also about 0.325” larger than a 10236.
The bottom area at the point of the notch on the 10242 is about 0.285” larger than a 10136.
This means there is a gradual taper from the middle to the bottom. Not sure if that is intentional by design or just from manufacturer tolerance.
Now, the 10142 is about 0.112” thick. The 10236 is about 0.130” thick. Not sure if that makes a difference in the weight offset, but I doubt it because the weight removed is also thicker.
The middle area you marked on a 10242 is about 0.325” larger than a 10136.
The top area at the point of the notch on the 10242 is also about 0.325” larger than a 10236.
The bottom area at the point of the notch on the 10242 is about 0.285” larger than a 10136.
This means there is a gradual taper from the middle to the bottom. Not sure if that is intentional by design or just from manufacturer tolerance.
Now, the 10142 is about 0.112” thick. The 10236 is about 0.130” thick. Not sure if that makes a difference in the weight offset, but I doubt it because the weight removed is also thicker.
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Bobzilla
Well-Known Member
I made some reference lines through the centerline of some of the bolt holes. Then I took measurements so there would be additional reference points for anyone trying to draw the notch onto a neutral balance. 10230, which is basically the same thickness as the 10242. I will need to refine this later to clarify where to take the measurements, but it’s from closest points, not the center lines. Centerlines were only used to position the reference lines consistently. Also, this last picture is with “ENGINE SIDE” facing up.
Thanks a lot! will do the cut today holding my breath
good news - I know how much I should cut, bad news these plates have different thickness -
