XR Top Cap
 

I hear allot about making sure top cap is properly torqued to help prevent major headaches.

My setup has Latham stearing with a six bolt top plate of which 4 bolts are in XR cap. Are these the mounting points I should monitor or is there something hiding underneath?

Re: XR Top Cap
 

These are the correct points to keep tight. Some feel the stock top caps are not strong enough and a aftermarket top cap is stronger. It stabilizes the upper shaft in the housing, theoretically lessening the likelihood of failure. Usually the L-hand prop turns in a direction to load the torque on the top cap. GLH actually broke the top cap. I have upgraded mine to Max Machine Worx top caps as I am turning 645 H.P. and over 600 ft/lb torque on a 10,400 boat (382 Formula). The are $400 each. Others to consider are Teague and Billet Marine.

Re: XR Top Cap
 

Hey, Red,

I assume you did get my check?
Merry Christmas.

mc

Re: XR Top Cap
 

Yes, I recieved the check. Thanks! Get them bolted on yet?
Happy Holidays and a very good New Year to you too, my friend!

Re: XR Top Cap
 

SummerHeat,
What Red says is correct. The stock caps are not the strongest. The Merc ITS cap has a steel tower in it. The aftermarket caps are much thicker. When it comes to LH rotation the top cap is a weak point.
One thing to point out that not all caps are made the same. There are differences in the clearances from the Merc to Aftemarket caps. I have seen some very good units and some very bad. It all depends on the machining of the surfaces on the bottom of the cap. I also believe it is important to setup your clearances in the upper gear set to get proper lash of the gears. Changing caps can affect this and is an important part of setting up a drive. I would recommend thicker top caps in most all instances. In your case the steering wing plates will have to be moved or redsigned to accomodate new caps. I would start with a call to Latham to see what they offer in this case.
Hope this helps.

Dick

Re: XR Top Cap
 

Broke... Man that thing dun blowed up!!!!

I check everytime I put the plugs in now 35 ft/lbs specially the left one. Not a problem since still on stock cap.

Re: XR Top Cap
 

I was going to go with an aftermarket billet top cap for my XR's, however I had Mr. Gadgets/Dick measure them with a micrometer and the clearences on the bottom of the caps were way off---these were made by Jack Bailey also known as "Budah". Anyway, they were nice looking pieces and at first he sent me a pair for a standard Bravo One of which I will admit turned out to be very nice---better tolerances than the stock Merc's, but I needed them for the XR's and they ended up being way off and I got tired of waiting, so I just purchased the Merc ITS caps and had Dick machine off the steering bosses to clear my double wing plates. I will attempt to post some pictures of my set-up.

Re: XR Top Cap
 

Here are a few shots of the set-up on my drives with the Merc ITS style top caps used in conjunction with my MM double wing plates and Simrek "halo" driveshowers.

Re: XR Top Cap
 

Top view...

Re: XR Top Cap
 

Someone got their camera to work!!... Nice Pics Mark!!

Re: XR Top Cap
 

Mark

I got a pair from Jack too. I have not put them on yet because of the other problems that I've had. I had plenty of time to wait.

How can you tell the difference between the Bravo one and the XR caps? Is it something you can measure. I have the caps at home and the boat is 70 miles away in the shop. I only have four months if I need to exchange them.

When the cap on my drive broke, the metal parts fell into the gears destroyed the entire drive. Its worth the money to get the aftermarket caps.

Re: XR Top Cap
 

Roger, I guess I could go into a lot of detail here, but when the first top caps arrived Dick (Mr. Gadgets) did a quick comparison check and found that they were standard Bravo Caps. Nice caps, but the wrong ones. Anyway, I gave them the bennefit of the doubt and tried to work it out with them, and over time I just told them to cancel the order---not worth the grief. Of course that was pretty minor compared to later stuff.

Re: XR Top Cap
 

Mark

Someday I would like to hear that story but not on here.

What was the difference between the Bravo One and XR cap? Is the bolt pattern or bearing size different?

Re: XR Top Cap
 

Q Storm,
The difference is in the bearing. The standard Bravo cap has a taller bearing race. I find out later that.. they can be used. After we put ITS caps on Marks drives. I found out that you can put the smaller XR bearing race on a standard cap and it will clear the gear and work. Sorry I didnt find this out till later Mark. The nice thing about the ITS cap is that it has a steel tower in it. I am running one on mine drive.
One thing to make sure of with the caps that jack built is that the surface that the bearing race (shim) sits in, is parallel and the right distance from the cap mounting surface. A normal Merc XR cap is .255" down from the cap mounting surface. The standard cap is .265" from the cap surface. I have seen the numbers all over the place. IMHO, any new cap should be measured and the setup shimmed accordingly to set the proper gear lash.
I hope this helps.

Dick

Re: XR Top Cap
 

ITS cap is a real good cap, though I have been using MAX MACHINE WORX caps this summer. MAX caps must weight 5 or 6 pounds and is 2" thick. Its machined out of billet and has a chrome moly tower. Comes w/ ARP stainless stud kit.You can get an awesome drive shower kit too.Sutphen30 and myself are very impressed w/ MAX goodies.

Re: XR Top Cap
 

Dick

That does help. I'll measure and match the step when I replace them.

Thanks

Roger

Re: XR Top Cap
 

Glad to be of help Roger!

Re: XR Top Cap
 

Dick, you all healed up yet? When can we do dinner at 84 East?

Re: XR Top Cap
 

Lot better than I was.. 98% normal.. if normal is normal..
We should look at a nite in the next couple of weeks.. now that summer has returned..
I'll talk to the better half and give you a call.
Dick

Re: XR Top Cap
 

The issue with thicker caps is heat retention and ease of cooling, this was brought up to me by my brother (engineer!).
His point was;
A. It might be harder to cool a stainless cap because thermal retention in stainless is better than aluminium.
B. Expansion between the stainless cap and aluminium housing will be different and might bring forth loosening issues after use.
C. The last thing he mentioned was that since the failure that happened on my boat was self inflicted (not verifying the torque of the top cap nuts often enough) that if I would have had a tougher cap I might of damaged the housing instead of the cap blowing off.

I decided to stick with the stock cap since it's the same material, although it looks like the ITS cap might be the best item if it fits conventional XR's. And Simek drive showers.

Re: XR Top Cap
 

The replacement caps that I have are aluminum. I was going to use the drive showers with the replacement caps. I know I would have to put another hole in the cavitation plate but the Simrek requires that too.

Re: XR Top Cap
 

According to Mr. Gadgets the Merc ITS top cap looks to be a much better casting process as far as he could see with his eye. This of course is in comparison to the Merc standard top cap.

Re: XR Top Cap
 

Dick, call me if you need my phone numbers. :p

Re: XR Top Cap
 

Sounds like it would be far superior to the crap budah was trying to pawn off on people.

Re: XR Top Cap
 

What should a merc i.t.s. cap cost? Where is the best place to buy them?

Re: XR Top Cap
 

KAAMA
are you using drive shafts or imco shafts in your boxes
thanks

Re: XR Top Cap
 

mcraymond,
give Sterndrivespec a call. his number is 315-623-7642. He will have a good price on them.

Dick