Seat Bottom Frame: Service and Repair

Repairing Damaged Female Threads on Seat Frame






Thread insert


NOTE: Damaged female threads on the magnesium seat frame can be repaired with aluminum helicoil thread inserts.


For reasons of corrosion and strength use only helicoil thread inserts from Bollhoff and Co. (version AI-F51 hard coated) approved by Mercedes-Benz with sizes M4-M8. (See parts ordering note below)

Always observe sequence of work steps when repairing.

Commercially available tools and test instruments

Designation
e.g. company, order no.
Manual installation tool for M4-M8 helicoil thread inserts
Bollhoff & Co. GmbH KG
Postfach 14 02 40
ArchimedesstraBe 1-4
D-33649 Bielefeld 14
Telephone (0521) 4482-01
Telefax (0521) 4493-64

or

Hahn & Koib Werkzeuge GmbH
Stuttgart-Feuerbach
BorsigstraBe 50
70469 Stuttgart
oder Postfach 10 60 18
70049 Stuttgart
Telephone (0711) 945-0
Telex (723 060-20/21 hk d
Telefax (0711) 945-2354
Teletex 711553
Btx *31658#






Parts ordering note

Procedure
1 Expose damaged thread, remove seat, if necessary.







2 Drill core hole (d3) with standard commercial spiral bit (see core hole table for diameter).






Core hole table for helicoil thread inserts (dimensions in mm)


3 Cut installation thread for helicoil thread insert with special helicoil tap.
4 Remove metal chips.
5 When finished paint edges of thread with repair paint, part no. 001 986 03 37.


NOTE: The helicoil thread inserts must be screwed in while the paint is still wet.







6 Insert helicoil thread insert into pretensioning cartridge of manual installation tool and screw into pretensioning cartridge flush by turning spindle on thread insert.
7 Position manual installation tool (4) on thread hole and screw helicoil thread insert into installation thread by continuing to turn spindle.


NOTE: Always ensure that helicoil thread insert is screwed in at least 1/4 to 1 1/2 turns below surface of part and is seated only in fully cut thread.







8 Remove driver lug with helicoil lug breaker on helicoil thread insert.


NOTE: It is not necessary to remove the driver lug in blind holes. In this case ensure that the maximum bolt screw-in depth is always maintained.


9 Reassemble front seat frame and install. Observe tightening torques!