Hi,
I want to let you know that the Exedy Stage 2 friction & steel kit fits the 6HP26 gearbox in the X350. I took my gearbox to a shop where I had it rebuilt, I had new solenoids in the valve body, but also the Exedy frictions & plates kit for the 1000hp Mustangs. I was afraid it won't work for the 6HP26, because it was made for the 6R80 (basically the 6HP28), even though Exedy said it works for the 26 too.


I tried inserting pics along the way, but they are put into the beginning of the post with no option to move them, so I'll attach them.


I got the gearbox torn apart, and I found out the Exedy frictions & steels are a perfect fit! Only difference is that unlike the 6r80, the 6hp26 hasn't got the drum heights, so in some places there was a disk that wouldn't fit. Don't fret however, because there are more clutches than standard, and the material is heavy duty. So if there are twin screw 4.2 XKRs out there which are fine with the stock 6hp26, I suspect that in this configuration, the 6 speeder would accept upwards of 1000Nm, no problem.


The big unknown, in my opinion, is the torque converter. My torque converter clutch was dying, so I changed it with a band of more surface area, and made from a heavy duty composition. It takes roughly 30% torque more than stock, but is that all to it? Theoretically, above 2000rpm, the TCC is always locked, so the turbine, stator etc. doesn't matter.... right?


After all was done, everything was put back together, and the trans bolted up. I took only a short test drive, I want to let it break in before I go full throttle. The good news is, if anyone wants to go all-out with Avos' TS, and doesn't have the tough MB gearbox, we now know the clutch packs can stand whatever you throw at them. So that means that if you also upgrade the TCC, the input shaft is now the limit. From our Australian friends, I understand that's about 500rwkw (~600rwhp), so that's not too bad!

 

Nice! Yes would love to see those pics! What were your costs if you don't mind me asking?
Thanks!

 

all taken apart, in preparation for the upgrade




getting the frictions out




Notice the increase clutch count from OEM. But not all the new clutches fit, because drum height in the 6r80/6hp28 is greater. Also, because of this, when putting the stage 2 clutches, one has to reuse the stock snap-ring, the one supplied is too thin, and there's too much play in the discs




new solenoids put in, work almost done




the old torque converter clutch, it was worn out




upgraded, full-width clutch band tor the TCC. I forgot to take the photo before the new one was put in.




if there are torque converter experts out there, by the look of it, how much power can go through this unit before furnace brazing & the rest of the mods is needed?




wrapping everything up

 

I want to apologize for the pics, I remember painstakingly uploading them one by one, but alas, to no avail, I see. I put a new post, which I see did the trick.


BlackKat, I don't know if costs are relevant to anyone in Western Europe, or the US, because labor is so much cheaper here. However, parts are almost twice as expensive as in the States, so perhaps it evens out. The Stage 2 clutches were around $500 (friend brought them, so no shipping + taxes), labor was 500 Euros. Solenoids + labor were 1000 Euros, and torque converter work + new clutch was 300 Euros.

 

Wow, amazing research and work!

Have you dyno tested your XJR at all?

 

Than you! I dyno'd it before any mods, and I got 291rwhp, after it was heat soaked from consecutive calibration runs, in July, at around 30 degrees Celsius. The most reliable marker is my trap speed, originally it was 166 km/h. After ECU, smaller pulley, intake elbow & mina induction kit, best was 171 km/h. After the supercharger rebuild & port, coupled with an even smaller pulley, and ported intake along with 81mm TB, I suspect I am at around ~175-176 km/h. I understand there is a rule of thumb for power levels such as ours, that every mph in trap speed is about 10hp, so theoretically I am about 60hp more than at the beginning. Note that perhaps I didn't make the full 400hp then.

 

now if only we could do something about that torque limitation. Or is that not an issue?

 

I haven't felt it, as I am not very far away from stock torque levels, but a funny thing that occurred was that in 4th, the car stopped accelerating at 5500rpm, like it had a speed limiter. I am investigating as for why this happened. Before the rebuild, the car refused to upshift from 3rd to 4th, and from 4th to 5th (only at WOT), it would just stay there at redline... if anybody has a clue as for why, please chime in

 

Hey any updates on this? Seems I have a transmission issue and an avos twin screw to add after I figure it all out


Thanks!

 

hey I stumbled upon this thread and I’m not sure if you had figured out the limiter but as for 2011 XF 5.0SC my limiter was set at 158 MPH. As for torque limitations set by TCM or ECU I have read that there are quite a few and not many TCU tuners are aware of some or don’t possess the ability to free them up. I believe the 6hp28 was said to be rated at 700nm/516.2935 FtLb of torque. Which if you’ve got the 5.0SC and mod it, doesn’t leave very much room for error. I appreciate your post as I am suspecting I have passed the stock 625nm/460FtLb torque already with more stuff planned. I think the Exedy Clutch kits for the 6R80 are much needed for reliability purposes. Glad it worked out for you and thank you again for the pictures and post!

 

Was the 6hp28 compatibility with these clutches confirmed by Exedy? I’ve looking into this for close to two weeks and haven’t found a single thing stating wether or not the HP28 would take the 6R80 parts. I messaged a few businesses and have seen lots of parts list both the 26 and 28 as specified vehicles so I had the idea they were nearly the same and I knew the 26 would take the 6R80 parts.
I need to rebuild my HP28 and wanted to do this upgrade.
Also did you have the torque converter serviced or replaced? Transmission pump?
If you watch the video, it is essentially what I was hoping to do if I were able to find out definitively that it would fit my trans. Thank you for your post. It has relit my hope for more reliable means to put future power to the ground.