Lambretta TS1 225 installation - fitting the drive-side & magneto bearings

Click here for bearing removal instructions

These pages aren't a step by step guide to fitting a TS1 and assume you already have some mechanical knowledge and experience of working with Lambretta engines. Despite the heading most of these steps are fairly generic for bearing replacement. The only difference with a TS1 is the use of high quality, high load bearings. Don't be tempted to cut costs here & use Indian bearings, German or Japanese are the best. For a list of bearings and oil seals see the table at the bottom of this page or click here.

As the heading mentions this is an installation so all the necessary disassembly has already been done inc. dismantling the engine & magneto side.   

1. Remove the existing oil seal from the plate.   9. ... and the drive side. 
2. The plate has a small lip to it on the side where the crank cheek sits. 


10. Here I've fashioned a tool using old bearings & a large nut  & bolt to pull the bearing into the heated housing.  Ensure the bearing goes in straight & doesn't twist.
3.  This picture shows the oil seal loosely fitted. This needs to be pressed in so that it is flush with the plate face (see 5.) Note the orientation of the oil seal. 11. Once the bearing has been fitted check that there is sufficient recess for the crank seal plate & the hallite washer to fit flush. 
4. This is the other side of the retaining plate. The oil seal spring should always face the crank web cheek. 12. Here's another view of the recess showing the required clearance.
5. This picture & the next show the oil seal correctly seated into the crank seal plate & ready to be fitted. 13. Apply some grease to the hallite washer & fit this into the recess. Ensure it is flush & covers the drive side bearing edge.
6. Crank seal plate with oil seal correctly fitted & orientated. 14. With the hallite washer fitted the crank seal plate is now ready to be fitted. 
7. Here are all the  required components for drive side re-assembly inc. a hallite washer & a brand new 6305 decent quality (SKF, FAG etc.) high load bearing (see bearings section below) 15. Fit 4 new screws & tighten these as much as possible. You may want to use an impact screwdriver to get these sufficiently tight & perhaps some loctite (see below) to hold the screws (ensure the holes are grease free)

SCREWS NOTE: Instead of the crappy screws that most dealers sell, try to use TORX screws. This style of drive is both strong and neat and a good choice for this application.

LOCTITE NOTE: Try not to use loctite as there are many different strengths available for different aplications. If I have to, I always use the one that states 'for parts that need to be disassembled' Most definitely do not use stud lock or bearing retainer!

8. Now seriously heat up the drive side bearing housing from both the magneto side ... 16. I tend to use a centre punch on the edge of the screws instead of loctite to secure these.

Lambretta Series III engine bearings & seals

Bearings and seals are a specialist area, if you have trouble locating any of these listed below I recommend you check with M.B. Developments as they only use the best.

Bearings Oil seals
Flywheel/Magneto side: NU2205 ECP (GP200 crankshaft only) or NU205E (all others) Bearing size: 25x52x15)

The NU2205 ECP prefix apparently refers to "Extra Capacity Plastic Cage" This has an improved inner construction, resulting in better lubrication and the ability to sustain higher loads.

Magneto side: 33-52-6 & 25-42-6
Drive side: 6305 C3 (size: 25x62x17) Use a decent brand i.e. SKF/FAG and always select "C3" 6305 bearings.

There are various types of bearing available including 6305-2RS1. The prefix means that the bearing has removable sides. 2RS denotes rubber shields, whereas 2Z or ZZ means it has 2 metal shields. In either case remember to remove one before fitting to allow oil in!

Innocenti engineers found that when fitting standard 6305 drive side bearings to engines these would quickly wear out. This was due to expansion caused by excessive heat from the crankshaft and cylinder cycles. The C3 has a radial internal clearance that is greater than a normal 6305. They are marked either "000" or "C3" and are found to last a lot longer in high performance engines.

Drive side: 33-50-6

For the drive side oil seal try to find double lip seals, these will have an AS suffix. This seal faces the gearbox and helps to prevent oil seepage into the crankshaft area should the gearbox become "pressurised" i.e. filler plug breather hole becomes clogged. The additional lip is used to prevent damage to the main sealing lip from external contaminants. However they raise the low pressure aspect of the seal to a seal that can hold up to 5 bar i.e. good for crankshafts. However twice as many sealing surfaces means twice as much friction. This "double lip" seal was originally produced by a company called "Rolf" and are now available from different manufacturers and in different materials i.e. Corteco (blue in colour) and Viton (brown). Viton material can be identified by the FPM prefix and these are very resistant to oil/petrol and cope with higher temperatures (200C) Therefore a Lambretta drive side Viton seal with a double lip would be FPM33x50x6AS.

A special stepped Lambretta bearing is used for the rear wheel Rear wheel: 32-45-6
Gear box end plate bearing: 6004 (all models)
Front wheel bearing 6201 (all models) Inner needle roller (fits into casing): 16-22-12 / 16-20-12
Layshaft endplate inner race: 20*24*10 Kick start shaft 22-32-5.5

Small end needle roller: 16*20*20

Mainshaft inner needle roller: 16*22*12

Avoid cheap needle roller gearbox bearings as these will fail! Try to find INA needle roller bearings which are made in Germany made. These are manufactured from higher grade steel and are precision ground to finer tolerances than the Indian equivalents. Unfortunately they're not cheap and retail between for 5 and 6.50 each. However they will not fail and will outlast any engine rebuild.
Props to Jem Booth and others for some of the information on this page.