Always the biggest fear when removing exhaust manifold studs is snapping them off in the head once that happens you have a real problem getting them out. The old way was using a torch now they have a new invention called an induction stud removal kit that is a game changer works like magic. Check it out could save you a huge headache 

I’ve done this repair on my 2005 Windsor with the 400 Cummins and used a penetrating lube called DeepCreep it works great multiple applications before you start the job ..once I removed the manifold I sent it to an engine machine shop to have it refaced and was badly warped since then it’s been fine  

17 hours ago, Doug Hoegh said:

Update our situation. After talking with my Allison dealer in Denver they showed me how to receive additional codes through the keypad. So I have three. 1. 6th gear not synch’d 2. Second gear not synch’d 3. Second gear valve stuck closed. The last code sunk my hopes for a quick fix. This valve is in the valve body assembly accessed by dropping the pan. So started to call around for help. Dealer in Whitehorse is 2 1/2 weeks out and couldn’t guarantee even then when they could get to me plus it’s a 250 mile tow round trip because there isn’t any heavy towing or trucks in Haines. Next option was Anchorage. If it’s even further away. So we made the decision to abandon Alaska and we a loading the coach on the Alaskan Ferry System and sailing to Seattle. Even that isn’t easy with the next open scheduled ship July 10th. So we are hanging in Haines until July with an appointment with Northwest Freightliner an authorized Allison dealer in Mt Vernon Washington. 

Ouch..that sucks Doug…my thoughts as a motor home owner would be tow it to Whitehorse or Lowbed it and there is some truck repair places there leave it to get repair remember you have American money to our Canadian 73 cent dollar fly home or rent a car do a trip to Dawson city or something while repairs are done. To ship it by ferry isn’t cheap 

On 6/19/2023 at 8:41 AM, Doug Hoegh said:

06 Diplomat with ISL400/Allison 3000.  On our way to Alaska my transmission went into limp mode and is stuck in third.   When it does this the two digit display on the shift pad indicates the right digit only as three and the check transmission light comes on. If I stop and turn off the coach the check transmission light will go out and the keypad goes back to 6/1. But then if accelerating goes back to the single 3 and check light returns. From the research I’ve found it either points to a sixth speed ratio issue or a speed sensor issue. We are in Haines and I can’t find any help so far but still looking. I’m going to confirm the connections at the twenty pin connector is tight and. It damaged. Looking for any other ideas. Thanks. Doug

That sucks Doug…and you haven’t even started on destruction highway parts of the Alaska highway if your in Haines. I’m thinking it’s a sensor or chafing wire issue the fun part is finding it. Have you tried manually shifts with the up and down buttons a friend had similar issues. It turned out his batteries were bad and didn’t have enough voltage to talk to the computer. Good luck hopefully you get to anchorage 

On 6/13/2023 at 7:03 PM, klcdenver said:

Take a cutting torch and cut the heads off the bolts so you can get manifold and turbo out. Weld nuts back on the studs to extract them without interference from everything. Good luck.

 Flameless Portable Magnetic Induction Heater…Is the newest tool for removing studs without burning up your coach. It uses induction technology to heat up just the stud and nothing else around it for easy removal